ajutooor urgeeenttttttt

Răspuns:
sinx=1/3
cos ²x=1-sin²x
cosx=√1-1/9=1/3√8=2√2/3
tgx=(1/3)/(2√2/3)=1/(2√2)=√2/4
sin2x=2sinxcosx=2(1/3)(2√2/3)=4√2/9
cos2x=1-2sin²x=1-2×1/9=7/9
ctg2x=(ctg²x-1)/2ctgx
dar ctgx =1/tgx=4/√2=2√2
ctg2x=(8-1)/4√2=7/(4√2)=7√2/8