Question

Let $y=\underset{2}{\overset{x}{\int }}\cos \left(\pi t^3\right)dt$, then equation of tangent line at $x=2$, is

• A. $x+y=2$
• B. $x+y=3$
• C. $x-y=2$
• D. $2x-y=3$

Answer 1

Answer: (C)

$\text{ at }x=2,y=0$
$\frac{dy}{dx}{|}_{x=2}=\cos \left(\pi x^3\right)=1$
$y-0=1(x-2)$
$x-x-y=2$