Compound trig (1 Viewer)

[kazemagic]

So I was doing some revision on trig and I came across these questions that I've no idea how to do :/
Q14)b in the image below

and Q19)b)c)

Thanks

 

[RealiseNothing]

14: (a)



Let:





So you get:



(b):





Let:





Then we get:



But

 

[kazemagic]

14: (a)



Let:





So you get:



(b):





Let:





Then we get:



But

ohh dayyuum thanks MC

 

[RealiseNothing]

19 (a)

(b) :



Let







(c) :

Solve the quadratic:



Use the quadratic formula:





But is in the first quadrant and hence positive, therefore:

 

[kazemagic]

19 (a)

(b) :



Let







(c) :

Solve the quadratic:



Use the quadratic formula:





But is in the first quadrant and hence positive, therefore:

ahh i c thx )