Trigonometric Ratios CBSE NCERT Solutions Chapter 8 Exercise 8.1 Question 9
9. In
, right angled at B, if tan A =
, find the value of
(i) sin A cos C + cos A sin C
(ii) cos A cos C – sin A sin C
Solution:
tan A =
tan A = (Side Opposite to Angle A) / (Side Adjacent to Angle A) =
Let BC = 1.k and AB =
as we are given that
Using Pythagoras Theorem on
, we get
sin A = (Side Opposite to Angle A) / (Hypotenuse) =
cos C = (Side Adjacent to Angle C) / (Hypotenuse) =
cos A = (Side Adjancet to Angle A) / (Hypotenuse) =
sin C = (Side Opposite to Angle C) / (Hypotenuse) =
(i)
sin A cos C + cos A sin C =
=
(ii)
cos A cos C – sin A sin C =
abishek says
It is good to understand