I need help with trygonometry

Question

Calculate:

(cos³x + 3sin³x)/cosx

Tg = 3/4

Answer 1

tg means tangent in trigonometry

so, I'll assume you mean tangent

(cos^3x+3sin^3x)/cosx

(cos^3x/cosx)+(3sin^3x/cosx)

cos^2x+(3sin^2x)(sinx/cosx)

cos^2x+(3sin^2x)(tanx)

cos^2x+(3sin^2x)(3/4)

cos^2x+(9/4)(sin^2x)

cos^2x+2.25sin^2x

cos^2x+sin^2x+1.25sin^2x

1+1.25sin^2x