/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 64 Verify the identity. $$\sin ^{... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Verify the identity. $$\sin ^{4} x+\cos ^{4} x=1-2 \cos ^{2} x+2 \cos ^{4} x$$

Short Answer

Expert verified
Yes, the given identity is true

Step by step solution

01

Express \(\sin^4{x}\) in terms of \(\cos^{4}{x}\)

Begin by expressing \(\sin^4{x}\) as \((1-\cos^2{x})^2\). This results in a purely cosine expression \((1 - \cos^2x)^2 + \cos^4x\).
02

Simplify the expression

Now expand the term \((1-\cos^2{x})^2\) to get \(1 - 2\cos^2x + \cos^4x\) and then add the \(\cos^4x\) term that we have from the initial equation. This results in \(1-2 \cos ^{2} x+2 \cos ^{4} x\).
03

Confirm the identity

Comparing the result with the right side of the original identity, it is seen that they are indeed the same. Hence, the identity is confirmed.

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