Question

the expressiion cos^2A-cos2A is equivalent to?

Answer 1

sin^2 A or more clearly written as (sin A ) ^2

Answer 2

cos squared a

Answer 3

Is that the answer you computed? I need to check my work.

Answer 4

i have no answer. i have a question cos^2 A - Cos2A

Answer 5

I didn't follow when you wrote "cos squared a" just now. I thought you were saying that is the answer.

Answer 6

oh no. sorry

Answer 7

Is cos squared a another problem to work or simplify?

Answer 8

no i just have one question

Answer 9

the expression cos squared a - cos 2 a is equivalent to what

Answer 10

i have 4 answer choices

Answer 11

sin squared a
-sin squared a
cos squared a + 1
-cos squared a - 1

Answer 12

sin squared a is the answer.

Answer 13

can you explain please?

Answer 14

cos2A = cos^2A - sin^2A
cos^2A -(cos^2A - sin^A)

the answer is sin^2A

Answer 15

cos^2A-cos2A = (1 - sin² A) - [ 1 - 2 sin^2(x) ] = 1 - sin² A - 1 + 2 sin² (x) =

sin² (x) ==> Answer

Notes:

sin^2(x) + cos^2(x) = 1 --> Identities to memorize

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

http://www.math.com/tables/trig/identities.htm