Answer:
Step-by-step explanation:
sin2x=2sinxcosx=2*3/√10*1/√10=6/10=3/5
cos2x=cos^2x-sin^2x=1/10-9/10=-8/10=-4/5
tan2x=sin2x/cos2x=3/-4=-3/4
..
Check:
sinx=3/√10
x=71.565
2x=143.13
sin2x=sin(143.13)=0.6000
exact value as computed=3/5=0.6000
cos2x=cos(143.13)≈.0.7999
exact value as computed=4/5=0.8000
tan2x=tan(143.13)≈-0.7500
exact value as computed=-3/4=-0.7500
