Question 745827
Evaluate sin(cos^-1(-6/7)) showing all steps as if you didn't have a calculator.
{{{cos(x)=-6/7}}}
{{{sin(x)=sqrt(1-cos^2(x))}}}
{{{sin(x)=sqrt(1-(6/7)^2)}}}
{{{sin(x)=sqrt(1-(36/49))}}}
{{{sin(x)=sqrt(13/49)}}}
Check: with calculator
cos(x)=-6/7
x≈149º
sin(x)=sin(149)≈0.5150
exact ans: √(13/49)≈0.5150