Question

Можете помочь))) с1; с2 и с3. Очень надо

Answer 1

$C1.;4cos xsin x-3sin^2x=1\ 4cos xsin x-3sin^2x=cos^2x+sin^2x\ cos^2x+sin^2x-4cos xsin x+3sin^2x=0\ cos^2x-4cos xsin x+4sin^2x=0\ (cos x-2sin x)^2=0\ cos x-2sin x=0\ 2sin x=cos x\ tgx=frac12\ x=arctgfrac12approx27^o=frac{3pi}{20}+pi n,;ninmathbb{Z}$

$xinleft[-frac{3pi}2;;frac{5pi}4right]Rightarrow -frac{3pi}2leqfrac{3pi}{20}+pi nleqfrac{5pi}4\ -frac{3pi}{2}-frac{3pi}{20}leqpi nleqfrac{5pi}4-frac{3pi}{20}\ -frac{33pi}{20}leqpi nleqfrac{22pi}{20}\ -frac{33}{20}leq nleqfrac{22}{20}\ -1,65leq nleq 1,1\ ninmathbb{Z}Rightarrow nin[-1;1]:\ n=-1Rightarrow x = frac{3pi}{20}-pi=-frac{17pi}{20}\ n=0Rightarrow x=frac{3pi}{20}\ n=1Rightarrow x = frac{3pi}{20}+pi=frac{23pi}{20}$