Question #6d140

1 Answer
Mar 31, 2015

You're almost there. Just use the fact that #cos^{2}(x)=1-sin^{2}(x)# and #\cosh^{2}(y)=1+sinh^{2}(y)# to substitute and simplify.

#|\sin(z)|^{2}=\cos^{2}(x)\sinh^{2}(y)+\sin^{2}(x)\cosh^{2}(y)=(1-\sin^{2}(x))\sinh^{2}(y)+\sin^{2}(x)(1+\sinh^{2}(y))=\sinh^{2}(y)-\sin^{2}(x)\sinh^{2}(y)+\sin^{2}(x)+\sin^{2}(x)\sinh^{2}(y)=\sin^{2}(x)+\sinh^{2}(y)#