Question

If cos x = sin(20 + x) ° and 0°

Answer 1

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 )