Question

Cos2 a-sin2 a =tan2 b then show that tan 2 a =cos 2b-sin2 b.

Answer 1

Cos^2b = 1/(tan^2b + 1)

Sin^2b = tan^2b/(1+tan^2b)

Then, Cos^2b - Sin^2b = (1 - tan^2b)/(1+tan^2b) (1)

By assuming that the input statement is: sin^2a - cos^2a = tan^2b (the original could have a typing error)

The expression (1) is: 

Cos^2b - Sin^2b
= (1 - sin^2a + cos^2a)/(1 + sin^2a - cos^2a) But sin^2a + cos^2a = 1

Cos^2b - Sin^2b
= (1 - (1-cos^2a) + cos^2a)/(1 + sin^2a - (1-sin^2a))

Cos^2b - Sin^2b

= 2 cos^2a/ 2 sin^2a

= 1/cot^2a

=tan^2a

Answer 2

Answer:

hfjdjdjdjdjdjdjdjsjsjdjjdjsjsjsjdjdjdjjdjdjsjsjsjsjdjxjchhchxhxj

Step-by-step explanation:

cjfndbdhjcjdbsnsjcikdjanshhc