Question

Prove that cos² theta ( 1+tan²theta)=1
​

Answer 1

Answer:

.......................

Answer 2

Question : Prove that cos²∅ (1 + tan²∅) = 1

SOLUTION :

cos²∅ (1 + tan²∅) = 1

We know that,

1 + tan²∅ = sec²∅

cos²∅ . sec²∅ = 1

We know that,

sec²∅ = 1/cos²∅

cos²∅ × 1/cos²∅

cos²∅/cos²∅ = 1

1 = 1

Some more Identities :

• sin²∅ + cos²∅ = 1

• 1 + tan²∅ + sec∅ = 1

• 1 + cot²∅ + cosec²∅ = 1