JAMB - Mathematics (1978 - No. 28)

If sec\(^2\) \(\theta\) + tan\(^2\) \(\theta\) = 3, then the angle \(\theta\) is equal to
30o
45o
60o
90o
105o

Explanation

sec\(^2\) \(\theta\) + tan\(^2\) \(\theta\) = 3

Where 1 + tan\(^2\) \(\theta\) = sec\(^2\) \(\theta\)

1 + tan\(^2\) \(\theta\) + tan\(^2\) \(\theta\) = 3

2 tan\(^2\) \(\theta\) = 2

tan\(^2\) \(\theta\) = 1

tan\(\theta\) = √1

where √1 = 1

tan\(\theta\) = 1

And  tan 45°  = 1 

∴ \(\theta\) = 45°

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