Question 1156473
a) Suppose a right triangle has hypotenuse 1 and one angle that is not the right angle {{{theta}}}. By the definition of sine and cosine, the legs have lengths {{{sin(theta)}}} and {{{cos(theta)}}}. By the Pythagorean Theorem, {{{sin^2(theta)+cos^2(theta)=1}}} multiplying both sides by 7 gets {{{7*sin^2(theta)+7*cos^2(theta)=7}}}.
b) Dividing {{{theta}}} by 4 in part a) gets {{{7*sin^2(theta/4)+7*sin^2(theta/4)=7}}}.