Decide whether the expression is or is not an identity.
-$$\sqrt { 1 - \cos ^ { 2 } x } = 1 - \cos x$$
A) Identity
B) Not an identity

Name: Decide whether the expression is or is not an identity. -\[\sqrt { 1 - \cos ^ { 2 } x } = 1 - \cos x\] A) Identity B) Not an identity
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Question

Quizplus · Accepted Answer

The expression is not an identity because $\sqrt { 1 - \cos ^ { 2 } x }$ simplifies to $|\sin x|$, not $1 - \cos x$. The original equation does not hold true for all values of $x$.

Decide Whether the Expression Is or Is Not an Identity 1−cos⁡2x=1−cos⁡x\sqrt { 1 - \cos ^ { 2 } x } = 1 - \cos x1−cos2x​=1−cosx

Decide Whether the Expression Is or Is Not an Identity $\sqrt { 1 - \cos ^ { 2 } x } = 1 - \cos x$