Question

answer this q third part only

Answer 1

Answer:

Ф = 45° or 60°

Step-by-step explanation:

(secФ -2 )(tan³Ф-1)=0

so we can say that either  secФ -2 =0   or tan³Ф -1 =0

HENCE  if

=> secФ -2 =0

=> secФ = 2

=> cosФ =1/2 = cos 60°

=> Ф = 60°

ELSE

=> tan³Ф -1 =0

=> tan³Ф = 1

=> tanФ =∛1= 1

=> tanФ = 1 = tan 45°

=> Ф =45°

Answer 2

Answer:

Hey mate please refer to the attachment