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Continuity and Differentiability — Maths STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceMathsContinuity and Differentiability1 Mark
MCQ
If $y=a x^2+b$, then $\frac{d y}{d x}$ at $x=2$ is equal to :
  • A
    $2a$
  • B
    $3a$
  • ✓
    $4a$
  • D
    None of these.
✓

Answer

Correct option: C.
$4a$
Given that, $y=a x^2+b$
Then, $\frac{\text{dy}}{\text{dx}} = 2\text{ax}$
At $x = 2, \frac{\text{dy}}{\text{dx}}=2(\text{a})(2)=4\text{a}$

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