Question 656136
<olo><li>Draw a right triangle and label one of the acute angles as "x".</li><li>Label the side opposite to x as "a", the side adjacent to x as "b" and the hypotenuse as "c".</li><li>From the Pythagorean Theorem we know that:
{{{a^2+b^2=c^2}}}</li><li>Divide both sides of the equation by {{{c^2}}}:
{{{a^2/c^2+b^2/c^2=c^2/c^2}}}</li><li>The right side simplifies to a 1 and we can use a property of exponents to rewrite the terms on the left side:
{{{(a/c)^2+(b/c)^2= 1}}}</li><li>Looking at the triangle we should be able to see that a/c = sin(x) and b/c = cos(x). Substituting these into our equation we get:
{{{(sin(x))^2+(cos(x))^2=1}}}</li><li>So the identity is simply the Pythagorean equation expressed in terms of Trig functions!</li></ol>