Class 10 Mathematics - Ch 6: Functions and Graphs
Change SetupClass 10 Mathematics - Ch 6: Functions and Graphs
Official curriculum roadmap, subject/topic distribution, negative marking rules, pacing guidelines, and solved sample questions.
🎯 Question Types & Curriculum Breakdown
💡 Strategic Preparation & Exam Hall Guidelines
To maximize your score on Class 10 Mathematics - Ch 6: Functions and Graphs, candidates are advised to follow a structured three-pass approach. In the First Pass, solve all direct recall and formula-based questions within 30 seconds each to secure foundational marks. In the Second Pass, tackle multi-step analytical and quantitative reasoning problems. In the Third Pass, review marked questions and verify calculations.
Practice with the interactive player below to evaluate your speed and accuracy under real exam pressure. Every question features full mathematical formulas, step-by-step worked solutions, and conceptual explanations vetted by Apex Rankers Academy subject matter specialists.
📝 Pre-Rendered Solved Sample Questions & Detailed Solutions
Review the solved problems below to understand question phrasing, answer choices, and step-by-step solution logic prior to starting the full interactive practice drill:
<p>$$A = \{2, 4, 6, 8\}, \quad B = \{1, 3, 5\}$$</p>
<p>$$R_1 = \{(2, 3), (6, 5), (8, 3), (4, 1)\}$$</p>
<p><strong>Step 1: Determine the domain of relation $R_1$:</strong></p>
<p>The domain consists of all first elements of the ordered pairs in $R_1$:</p>
<p>$$\operatorname{Dom}(R_1) = \{2, 6, 8, 4\} = \{2, 4, 6, 8\} = A$$</p>
<p><strong>Step 2: Check for repetition of first elements:</strong></p>
<p>Each element of set $A$ appears exactly once as the first component of an ordered pair. There is no repetition of any first element.</p>
<p><strong>Step 3: Check codomain membership:</strong></p>
<p>The second elements $\{3, 5, 1\}$ are all members of set $B$, so $\operatorname{Range}(R_1) \subseteq B$.</p>
<p><strong>Conclusion:</strong></p>
<p>Since $\operatorname{Dom}(R_1) = A$ and every element in $A$ is associated with a unique element in $B$, $R_1$ satisfies both criteria of a function.</p>
<p><strong>Final Answer:</strong></p>
<p>$$\mathbf{\text{Yes, } R_1 \text{ is a function from } A \text{ to } B.}$$</p>
<p>$$A = \{2, 4, 6, 8\}, \quad B = \{1, 3, 5\}$$</p>
<p>$$R_2 = \{(2, 3), (6, 1), (8, 3), (6, 5)\}$$</p>
<p><strong>Step 1: Check the first elements of the ordered pairs:</strong></p>
<p>Notice that the element $6 \in A$ appears as the first element in two distinct ordered pairs:</p>
<p>$$(6, 1) \in R_2 \quad \text{and} \quad (6, 5) \in R_2$$</p>
<p><strong>Step 2: Apply the definition of a function:</strong></p>
<p>By definition, a function cannot assign multiple distinct outputs to the same input element. Here, the input $6$ is mapped to two different images, $1$ and $5$.</p>
<p><strong>Step 3: Check domain completeness:</strong></p>
<p>Furthermore, element $4 \in A$ has no corresponding ordered pair in $R_2$, so $\operatorname{Dom}(R_2) = \{2, 6, 8\} \neq A$.</p>
<p><strong>Final Answer:</strong></p>
<p>$$\mathbf{\text{No, } R_2 \text{ is not a function from } A \text{ to } B.}$$</p>
<p>$$A = \{2, 4, 6, 8\}, \quad B = \{1, 3, 5\}$$</p>
<p>$$R_3 = \{(2, 3), (6, 5), (8, 3)\}$$</p>
<p><strong>Step 1: Determine the domain of relation $R_3$:</strong></p>
<p>Extracting the first elements of the ordered pairs:</p>
<p>$$\operatorname{Dom}(R_3) = \{2, 6, 8\}$$</p>
<p><strong>Step 2: Compare $\operatorname{Dom}(R_3)$ with set $A$:</strong></p>
<p>For a relation to be a function from set $A$ to set $B$, its domain must be strictly equal to set $A$ ($\operatorname{Dom}(f) = A$).</p>
<p>Here, $4 \in A$ but $4 \notin \operatorname{Dom}(R_3)$. The element $4$ has no image in $B$.</p>
<p><strong>Final Answer:</strong></p>
<p>$$\mathbf{\text{No, } R_3 \text{ is not a function from } A \text{ to } B.}$$</p>
<p>$$A = \{2, 4, 6, 8\}, \quad B = \{1, 3, 5\}$$</p>
<p>$$R_4 = \{(2, 3), (6, 3), (8, 3), (4, 1)\}$$</p>
<p><strong>Step 1: Determine the domain:</strong></p>
<p>$$\operatorname{Dom}(R_4) = \{2, 6, 8, 4\} = \{2, 4, 6, 8\} = A$$</p>
<p><strong>Step 2: Check uniqueness of images:</strong></p>
<p>Every element in $A$ appears exactly once as the first component of an ordered pair. There is no repetition in the first coordinates.</p>
<p><em>Note:</em> The second coordinate $3$ is shared by inputs $2, 6, 8$. In a function, multiple distinct inputs may produce the same output (many-to-one mapping). This is completely valid.</p>
<p><strong>Step 3: Verify range:</strong></p>
<p>$$\operatorname{Range}(R_4) = \{1, 3\} \subseteq B$$</p>
<p><strong>Final Answer:</strong></p>
<p>$$\mathbf{\text{Yes, } R_4 \text{ is a function from } A \text{ to } B.}$$</p>
<p>$$A = \{2, 3, 5\}, \quad B = \{1, 3, 5\}$$</p>
<p>$$f = \{(2, 3), (3, 5), (5, 1)\}$$</p>
<p><strong>Step 1: Check if $f$ is a function:</strong></p>
<p>$\operatorname{Dom}(f) = \{2, 3, 5\} = A$. Every element in $A$ has exactly one outgoing arrow (a unique image in $B$). Therefore, $f$ is a function.</p>
<p><strong>Step 2: Check if $f$ is One-to-One (Injective):</strong></p>
<p>Distinct elements of set $A$ have distinct images in set $B$ ($f(2) = 3$, $f(3) = 5$, $f(5) = 1$). No two arrows point to the same element in $B$. Thus, $f$ is one-to-one (injective).</p>
<p><strong>Step 3: Check if $f$ is Onto (Surjective):</strong></p>
<p>$$\operatorname{Range}(f) = \{1, 3, 5\} = B$$</p>
<p>Every element of the codomain $B$ has at least one pre-image in $A$. Thus, $f$ is onto (surjective).</p>
<p><strong>Conclusion:</strong></p>
<p>A function that is both one-to-one and onto is called a <strong>bijective function</strong>.</p>
<p><strong>Final Answer:</strong></p>
<p>$$\mathbf{\text{Yes, Bijective Function (One-to-One and Onto)}}$$</p>
<p>$$P = \{0, 2, 4\}, \quad Q = \{5, 7\}$$</p>
<p>$$g = \{(0, 5), (2, 7)\}$$</p>
<p><strong>Step 1: Examine the domain of mapping $g$:</strong></p>
<p>The domain of $g$ consists of all elements in $P$ that have outgoing arrows:</p>
<p>$$\operatorname{Dom}(g) = \{0, 2\}$$</p>
<p><strong>Step 2: Compare $\operatorname{Dom}(g)$ with domain set $P$:</strong></p>
<p>$$\operatorname{Dom}(g) = \{0, 2\} \neq P = \{0, 2, 4\}$$</p>
<p>The element $4 \in P$ is not mapped to any element in set $Q$ (it has no image).</p>
<p><strong>Conclusion:</strong></p>
<p>By definition, a function from set $P$ to set $Q$ requires that every single element in set $P$ must have an image in $Q$. Since element $4$ has no image, $g$ is not a function.</p>
<p><strong>Final Answer:</strong></p>
<p>$$\mathbf{\text{No, } g \text{ is not a function.}}$$</p>
<p>$$X = \{0, 2, 4\}, \quad Y = \{a, b, c\}$$</p>
<p>$$h = \{(0, b), (2, c), (4, c)\}$$</p>
<p><strong>Step 1: Check if $h$ is a function:</strong></p>
<p>$$\operatorname{Dom}(h) = \{0, 2, 4\} = X$$</p>
<p>Every element in $X$ has exactly one outgoing arrow to set $Y$. Hence, $h$ is a function.</p>
<p><strong>Step 2: Find the range of $h$:</strong></p>
<p>$$\operatorname{Range}(h) = \{b, c\}$$</p>
<p><strong>Step 3: Compare range with codomain set $Y$:</strong></p>
<p>Notice that $\operatorname{Range}(h) = \{b, c\} \subset Y = \{a, b, c\}$.</p>
<p>Element $a \in Y$ has no pre-image in $X$ (no arrow points to $a$), which means $\operatorname{Range}(h) \neq Y$.</p>
<p><strong>Conclusion:</strong></p>
<p>A function $f: X \to Y$ is called an <strong>into function</strong> if there is at least one element in set $Y$ which is not the image of any element of set $X$ ($\operatorname{Range}(f) \subset Y$).</p>
<p><strong>Final Answer:</strong></p>
<p>$$\mathbf{\text{Yes, Into Function.}}$$</p>
<p>$$f(x) = x^2 - \frac{1}{2}x + 3$$</p>
<p><strong>Step 1: Substitute $x = 2$ into the function:</strong></p>
<p>$$f(2) = (2)^2 - \frac{1}{2}(2) + 3$$</p>
<p><strong>Step 2: Simplify each term:</strong></p>
<p>$$(2)^2 = 4$$</p>
<p>$$\frac{1}{2}(2) = 1$$</p>
<p><strong>Step 3: Perform addition and subtraction:</strong></p>
<p>$$f(2) = 4 - 1 + 3 = 3 + 3 = 6$$</p>
<p><strong>Final Answer:</strong></p>
<p>$$\mathbf{6}$$</p>
<p>$$f(x) = x^2 - \frac{1}{2}x + 3$$</p>
<p><strong>Step 1: Substitute $x = -1$ into the function:</strong></p>
<p>$$f(-1) = (-1)^2 - \frac{1}{2}(-1) + 3$$</p>
<p><strong>Step 2: Simplify arithmetic operations:</strong></p>
<p>$$(-1)^2 = 1$$</p>
<p>$$-\frac{1}{2}(-1) = +\frac{1}{2}$$</p>
<p>$$f(-1) = 1 + \frac{1}{2} + 3 = 4 + \frac{1}{2}$$</p>
<p><strong>Step 3: Express as an improper fraction:</strong></p>
<p>$$4 + \frac{1}{2} = \frac{4 \times 2 + 1}{2} = \frac{9}{2}$$</p>
<p><strong>Final Answer:</strong></p>
<p>$$\mathbf{\frac{9}{2}}$$</p>
<p>$$f(x) = x^2 - \frac{1}{2}x + 3$$</p>
<p><strong>Step 1: Substitute $x = \frac{2}{3}$ into the function:</strong></p>
<p>$$f\left(\frac{2}{3}\right) = \left(\frac{2}{3}\right)^2 - \frac{1}{2}\left(\frac{2}{3}\right) + 3$$</p>
<p><strong>Step 2: Simplify each term:</strong></p>
<p>$$\left(\frac{2}{3}\right)^2 = \frac{4}{9}$$</p>
<p>$$\frac{1}{2}\left(\frac{2}{3}\right) = \frac{1}{3} = \frac{3}{9}$$</p>
<p>$$3 = \frac{27}{9}$$</p>
<p><strong>Step 3: Combine numerators over the common denominator $9$:</strong></p>
<p>$$f\left(\frac{2}{3}\right) = \frac{4}{9} - \frac{3}{9} + \frac{27}{9} = \frac{4 - 3 + 27}{9} = \frac{28}{9}$$</p>
<p><strong>Final Answer:</strong></p>
<p>$$\mathbf{\frac{28}{9}}$$</p>