Question

If you can do all of them please do, but I mainly need 11-13.

Answer 1

11. D. All of these

12.

sin30° =
`(1)/(2)`

cos 45°=
`(1)/(√(2) )`

cos 30°=
`(√(3) )/(2)`

tan 45°=
`1`

tan 30°=
`(1)/(√(3) )`

13. B tan 60°

Explanation:

11.Given,

ABC is a triangle with sides measures as
`AB=c , AC=b \ and\ BC=a`

We have to find the different trigonometric ratio,

We know,

`sin=(opposite)/(hypotenuse) \ and\ cos=(adjacent)/(hypotenuse)`

We observe,

`sinA=(a)/(c) \\cosB=(a)/(c)`

Therefore both are equal, option (A) is correct!

It is a rule that,

`sin(90-M) = cosM`

Thus option (B) is correct!

It is a universal proof that ,

`sin^2M+cos^2M=1`

Thus option (C) is true!

Therefore option (D) is the appropriate choice 'all of these' are correct!

12.

We know,

`sin=(opp)/(hyp) \\sin30=(1)/(2)`

We know ,

`cos=(adj)/(hyp) \\cos45=(1)/(√(2) )`

Similarly,

`co30=(√(3) )/(2)`

We know,

`tan=(opp)/(hyp) \\tan=(1)/(1) =1`

Similarly,

`tan30=(1)/(√(3) )`

13.

We know,

`(sin60)/(cos60) =√(3) \\tan60=√(3)`

Therefore B is the correct option!