Question

cos²x-sin²x=..........

Answer 1

cos²x - sin²x = cos 2x

Given : cos²x - sin²x

To find : The value

Solution :

Step 1 of 2 :

Write down the given expression

The given expression is

cos²x - sin²x

Step 2 of 2 :

Find the value

We are aware of the Trigonometric formula that

cos ( A + B ) = cos A cos B - sin A sin B

Taking A = x & b = x we get

cos ( x + x ) = cos x cos x - sin x sin x

⇒ cos 2x = cos²x - sin²x

⇒ cos²x - sin²x = cos 2x

━━━━━━━━━━━━━━━━

Learn more from Brainly :-

$1.$ if x cos a=8 and 15cosec a=8sec a then the value of x is

a) 20 b)16 c)17 d)13

https://brainly.in/question/46325503

2. 7 cos 30° + 5 tan 30° + 6 cot 60° is

https://brainly.in/question/46167849

3. 1+ sin2α = 3 sinα cosα, then values of cot α are

https://brainly.in/question/46265791

Answer 2

Answer:

cos²x-sin²x = 1-2sin²x      

Step-by-step explanation:

cos²x-sin²x=1-2sin²x

cos^2(x) = 1 - sin^2(x)

1-sin^2(x) - sin^2(x) = 1-2sin^2(x)

1 - 2sin²x=1-2sin²x

#SPJ2