Foundation
Mathematics Foundation
Introduction to Trigonometry
Question

If 7 tan θ = 4 then (7sinθ3cosθ)(7sinθ+3cosθ)=?

37

57

514

17

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Solution

Given 7 tan θ = 4, so tan θ = 4/7. We need to find (7 sin θ - 3 cos θ)/(7 sin θ + 3 cos θ).

Divide numerator and denominator by cos θ to express in terms of tan θ:

(7sinθcosθ-3)(7sinθcosθ+3)=7tanθ-37tanθ+3

Substitute tan θ = 4/7:

7×47-37×47+3=4-34+3=17

Final Answer: 17