Question

If y = cos x° then find \(\rm \frac{{dy}}{{dx}}\)?
1. sin x
2. -sin x
3. cos x
4. None of the above

Answer 1

Correct Answer - Option 4 : None of the above

Concept:

\(\rm \frac{{d}}{{dx}} (cos x) = - sinx\)

Degree to radian conversion: xo = \(\rm \frac{\pi }{180} \times x\)

Calculation:

x^o = \(\rm \frac{\pi }{180} \times x\)

Given, y = cos x°

⇒ y = cos \(\rm \frac{\pi x}{180}\)

⇒ \(\rm \frac{{dy}}{{dx}}\) = - \(\rm \frac{\pi}{180}\) sin \(\rm \frac{\pi x}{180}\)