Answer:
x = 35°
Step-by-step explanation:
The question is as following
cos x = sin(20 + x)° and 0° < x < 90° , find X?
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cos x = sin(20 + x)°
sin and cos are co-functions,
which means that: cos x = cos [90 - (20 + x)]
∴ x = 70 - x
∴ 2x = 70
∴ x = 35°
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Note: cos θ = sin ( 90 - θ )
