Question

Prove that :
sin² theta (1 + cos² theta ) = 1​

Answer 1

Answer:

Prove identity sin²0 + cos²0 = 1 , geometrically.

Solution

In right ∆ABC , angle B = 90°

By Pythagoras theorem ;

AC² =AB² +BC²

Dividing both sides by AC²

➝ AC² =AB²+BC²

AC² =AB²+AC²

➝1 = (AB)² + (BC)²

(AC). (AC)

Hope it will help you

➝sin² A + Cos² A=1 .