Question

упростите выражение 5 tg^2x cos^2X+5sin^2x ctg^2x

Answer 1

$5tg^2xcos^2x+5sin^2xctg^2x= 5frac{sin^2x}{cos^2x}cos^2x+5sin^2xfrac{cos^2x}{sin^2x}=5sin^2x+5cos^2x=5(sin^2x+cos^2x)=5cdot1=5$