## anonymous one year ago TRIGONOMETRY: Start with sin2(θ) + cos2(θ) = 1. What would you multiply through by to get sec2(θ) = tan2(θ) + 1?

1. anonymous

2. Nnesha

what is reciprocal of tan ?

3. DanJS

sorry, i was still on the closed first question of this

4. anonymous

cotangent @nnesha

5. anonymous

6. DanJS

try each answer out to see if it will work...

7. Nnesha

not just cot it should be 1/cot but how would you write tan in terms of sin cos ?

8. DanJS

you just need to know the basic definitions of the trig functions, and multiply through each anser to test if it works

9. DanJS

For example in using A) 1/cos^2(x) multiplying the given equation by that results in $\frac{ \sin^2(x) }{ \cos^2(x) }+\frac{ \cos^2(x) }{ \cos^2(x) } = \frac{ 1 }{ \cos^2(x) }$

10. DanJS

see if that is the same as the equation they are looking for

11. anonymous

I get tan^2(x), not sec.

12. DanJS

right, sin^2 / cos^2 = tan^2 for the first fraction

13. DanJS

do that for all 3

14. DanJS

cos^2 / cos^2 = 1

15. DanJS

and 1 / cos^2(x) = sec(x)^2 right

16. anonymous

17. DanJS

it appears so, because you get tan^2(x) + 1 = sec^2(x)

18. DanJS

memorize the 6 trig vunctions and how they relate... tha tis all this is