Question

In right angled ∆ABC, ZA= 90°, AB= 8 cm., BC = 17 cm.
Find Sin B, Cos B. Also prove that tan B x tan (90 - B)=1.​

Answer 1

Step-by-step explanation:

1) BC² -AB² = AC²

289-64= AC²

AC = 15

sinB =15\17

cos B =8\17

2) tanB ×tan(90°-B) = 1

formula used in this question=tan(90°-B) = cotB

= tanx ×cotx = 1

so given question

tanB× tan(90°-B) = 1

we take LHS

=tanB× tan(90°-B)

= tanB× cot B

= 1

LHS = RHS