If tan A = 10/15, then what will be the value of cos2 A ?
Answer & explanation
Correct answer: option 3
tanA = \(\frac{10 }{15}\)
By using pythagoras theorem ,
P2 + B2 = H2
102 + 152 = H2
H = 5√13
cos2A = (\(\frac{15 }{ 5√13}\))2 = (\(\frac{3 }{ √13}\) )2
= \(\frac{9 }{ 13}\)