## aussy123 2 years ago Given the point (3, 4), which of the following shows that sinxcscx = 1? (3/4)(4/3) = 1 (3/5)(5/3) = 1 (4/5)(5/4) = 1

1. hartnn

Given the point (3, 4), can you find sin x=...?

2. aussy123

I think ......Ill show a graph

3. aussy123

|dw:1363005355574:dw|

4. hartnn

wait

5. Mertsj

|dw:1363005499577:dw|

6. hartnn

(3,4) means x-co-ordinate = 3 y co-ordinate =4, so it'll be |dw:1363005449516:dw| can you find the hypotenuse = b= ...? using pythagoras theorem ?

7. aussy123

yes

8. hartnn

then can you find sin x = opposite side/hypotenuse =... ?

9. hartnn

|dw:1363005619712:dw|

10. aussy123

a^2+b^2=c^2 3^2+b^2=4^2 9+b^2=16 b^2=7 $\sqrt{7}$

11. Mertsj

$a^2+b^2=c^2$

12. Mertsj

$3^2+4^2=c^2$

13. hartnn

you've taken incorrect sides... a= 3, b=4 find c=hypotenuse =..?

14. Mertsj

$9+16=c^2$

15. Mertsj

$25=c^2$

16. Mertsj

$5=c$

17. aussy123

oh Im sorry 9+16=25 c^2=25 5=c

18. hartnn

thats correct, now sin x = opposite side / hypotenuse =...?

19. aussy123

oh it 4/5

20. hartnn

yup, and csc x = hypotenuse/opposite side =...?

21. aussy123

5/4

22. hartnn

thats it, so (4/5)(5/4)=1

23. aussy123

Yayy Thanks, this was really helpful, Ill try this on the rest of my problems!

24. hartnn

welcome ^_^