Q6 of 123 Page 9

If then write the value of

Given, for the value of

Consider,

[by using the formula cos 2x = cos² x – sin² x]

[by using the formula cos² x + sin² x = 1]

As already mentioned in the question, , x is in the 3^rd quadrant, where tangent function is positive.

Therefore,

If then write the value of in the simplest form.

If then write the value of

In a right-angled triangle ABC, write the value of sin² A + sin² B + sin² C.

Write the value of cos² 76^o + cos² 16^o – cos 76^o cos 16^o.