Question

Please answer these need your help

Answer 1

Answer:

13. (D)

(because sin²75°+cos²75°=1)

14. (B)

{Given, sec∅=x, cosec∅=y which implies that sin∅= 1/y then tan∅=sin∅.sec∅=x/y}

15. (D)

(if tan∅= 15/8 then by Pythagoras theorem cos∅=8/17)

16. (A)

{ since x=sec∅+tan∅ & y=sec∅-tan∅ then

xy= sec²∅-tan²∅=1}

17. (D)

{(sin∅+cos∅)²= sin²∅+cos²∅+2sin∅.cos∅}

18. (C)

(if tan∅= 1/√3 then ∅= 30° therefore,

cos2∅= cos2(30°)=cos60°=1/2)

19. (A)

(if sin∅=√3/2 then ∅= 60°)

20. (C)

(if ∅= 45° then (1-cos2(45°))/sin2(45°) = (1-cos90°)/sin90° = (1-0)/1= 1 Ans.)

21. (A)

22. (C)

(if tan(A+B)=1 then A+B= 45°)

23. (A)

(if cos(A-B)=√3/2 then A-B= 30°)

I hope it is helpful for uh