Which identity is the Pythagorean identity?
sin2(theta)+cos2(theta)=1\\sin^2(\\theta) + \\cos^2(\\theta) = 1sin2(theta)+cos2(theta)=1
sin(theta)+cos(theta)=1\\sin(\\theta) + \\cos(\\theta) = 1sin(theta)+cos(theta)=1
tan2(theta)+1=0\\tan^2(\\theta) + 1 = 0tan2(theta)+1=0
sin2(theta)−cos2(theta)=1\\sin^2(\\theta) - \\cos^2(\\theta) = 1sin2(theta)−cos2(theta)=1