Chargement....

JAMB UTME - Mathematics - 1988

Question 1 Rapport

If \( \cos^2 \theta + \frac{1}{8} = \sin^2 \theta \), find \( \tan \theta \)

Détails de la réponse
cos2 θ  +  1 8  = sin2 θ ..........(i)
from trigometric ratios for an acute angle, where cos θ  + sin2 θ  = 1 - cos θ  ........(ii)
Substitute for equation (i) in (i) = cos2 θ  +  1 8  = 1 - cos2 θ
= cos2 θ  + cos2 θ  = 1 -  1 8
2 cos2 θ  =  7 8
cos2 θ  =  7 2 × 3
7 16  = cos θ
7 16  =  7 4
but cos  θ  =  adj hyp
opp2 = hyp2 - adj2
opp2 = 42 ( 7 )2
= 16 - 7
opp =  9  = 3
than  θ  =  opp hyp
=  3 7
3 7  x  7 7  =