Question

:) 2cos^2 a + cos a - 1 = 0
Find the value of
a

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Answer 1

Answer:

A 15

Step-by-step explanation:

Given, (2cos2A−1)(tan3A−1)=0

Either 2cos2A−1=0 or tan3A−1=0

cos2A= 21or tan3A=1cos2A=cos60 or tan3A=tan452A=60 or 3A=45 A=30

or A=15A=30 ,15

Hence, other value of angle A is 15.