Question

Упростить -4cos²α+5-4sin²α

Answer 1

-4cos^2α+5-4sin^2α=-4(cos^2α+sin^2α)+5=-4+5=1

Answer 2

$-4cos^2alpha+5-4sin^2alpha= -4(1-sin^2alpha)+5-4sin^2alpha= \ =-4+5+4sin^2alpha -4sin^2alpha=5-4=1$