If 3sec + 4 cos - 4 = 0 where is an acute angle then the value of is:
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Correct answer: D
Explanation
The correct answer is option 4 i.e. 30º
Instead of solving this equation we could just use the substitution method and make our life easy,
⇒ = 45o
⇒ 3 sec 45o + 4 cos 45o = 4√3
⇒ 3√2 + 4√2 = 5√2
This is not the correct answer.
⇒ = 60o
⇒ 3 sec 60o + 4 cos 60o = 4√3
⇒ 3(2) + 4(1/2)
This is not the correct answer.
⇒ = 30o
⇒ 3 sec 30o + 4 cos 30o = 4√3
⇒ 3(2/√3) + 4(√3/2)
⇒ 2√3 + 2√3 = 4√3
This is the correct answer.