Book- ML Aggarwal
Board- ICSE
Publication- Avichal
Chapter- Trigonometric Identities
If A is an acute angle and sec A = 17/8, find all other trigonometric ratios of angle A (using trigonometric identities).
This is important ques.. Pls provide solution with figure
ML Aggarwal, ques no 2
Solution:
sec A = 17/8 and A is an acute angle
So, in ∆ ABC we have ∠B = 90o
And,
AC = 17 and AB = 8
By Pythagoras theorem,
BC = √(AC2 – AB2)
= √(172 – 82) = √(289 – 64) = √225
= 15
Now,
sin A = BC/AC = 15/17
cos A = 1/sec A = 8/17
tan A = BC/AB = 15/8
cot A = 1/tan A= 8/15
cosec A = 1/sin A = 17/15