Question

find the value of m = cos2x+sin3x+tan4x,where x = x/2​

Answer 1

Given :

The value of m= cos2x+ sin3x+ tan4x

To Find :

We have to find the value of m.

Solution:

It is given that, m= cos2x+ sin3x+ tan4x

In order to get the value of m, we need to substitute the value of x= $\frac{\pi }{2}$ in the above equation.

We know the following trigonometric values,

                           $\[\begin{array}{l}\cos \left( {2 \cdot \frac{\pi }{2}} \right) = -1\\\\\sin \left( {3 \cdot \frac{\pi }{2}} \right) = 0\\\\\tan \left( {4 \cdot \frac{\pi }{2}} \right) = 0\end{array}\]$

By subtituting the above values we get,

                      m= cos2x+ sin3x+ tan4x

                         = -1+0+0

 ⇒                 m= -1

Hence, the value of m for the given equation is -1.