Question

7.
If sec A+ tan A =4, then sin A equals
(a) 8/15
(b) 15/17
(c) - 8/15
(d) 8/17​

Answer 1

Answer:

As we know,

sec^2A- tan^2A=1

= (secA- tanA)(secA+ tanA)= 1

= (secA- tanA) (4) = 1 (According to question)

= (secA- tanA) = 1/4

After solving,

secA- tanA = 1/4 and secA+ tanA=4

We get, secA= 17/8= hypotenuse/ base

= perpendicular= 15

sinA= perpendicular/hypotenuse= 15/17.

SinA= 15/17.