Question

If the tangent to the function $y = f(x)$ at $(3,4)$ makes an angle of $\frac{3 \pi }{4}$ with the positive direction of x-axis in anticlockwise direction then $f ' (3)$ is

• A. -1
• B. 1
• C. $\frac{1}{\sqrt{3}}$
• D. $\sqrt{3}$

Answer 1

Answer: (A)

-1

Answer 2

$f'(3) = \tan \frac{2 \pi }{4} = - \tan \frac{\pi}{4} = - 1$