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31 votes
31 votes
Solve for X when 7cos2x = 5

User Zigu
by
3.1k points

1 Answer

22 votes
22 votes

Answer: x = 22.21

Explanation:

Given

7 · cos (2x) = 5

Divide 7 on both sides

7 · cos (2x) / 7 = 5 / 7

cos (2x) = 5/7

Divide cosine on both sides (meaning applying cos⁻¹ to the right-hand side)

2x = cos⁻¹ (5/7)

Divide 2 on both sides

2x / 2 = [cos⁻¹ (5/7)] / 2


\boxed {x=22.21} (Rounded to the hundredth place)

Hope this helps!! :)

Please let me know if you have any questions

User Matheus Barem
by
3.0k points