Question

Given that 5 cos (x+8.5)° - 1 = 0

0° ≤x≤ 90, calculate correct to the nearest degree, the value of x.​

Answer 1

x = 70

Explanation:

To solve for x, use inverse operations to undo the operations performed on x.

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5cos(x +8.5)° -1 = 0 . . . . given

5cos(x +8.5)° = 1 . . . . . . add 1

cos(x +8.5)° = 1/5 . . . . . divide by 5

x° +8.5° = arccos(1/5) . . . . take the inverse cosine

x° = arccos(1/5) -8.5° ≈ 70° . . . . evaluate the expression

The value of x is 70.