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Double-Angle and Half Angle Identities. Double-Angle Identity. If represents the measure of an angle, then the following identities hold for all values of . If and terminates in the first quadrant, find the exact value of each function. -1.
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Double-Angle Identity • If represents the measure of an angle, then the following identities hold for all values of .
If and terminates in the first quadrant, find the exact value of each function. -1
If and terminates in the first quadrant, find the exact value of each function. • we must first find the
If and terminates in the first quadrant, find the exact value of each function.
Half-Angle Identities • If represents the measure of an angle, then the following identities hold for all values of .
Use a half-angle identity to find the exact value of each function. Since 15⁰ is a first quadrant angle and sine is positive in the first quadrant, choose the positive value.
Use a half-angle identity to find the exact value of each function. Since 135 is a second quadrant angle and cosine is negative in the second quadrant, choose the negative value. Thus,