How do you rewrite y=-4cos(2x+(pi/2))+1 as a sine function? Trigonometry Right Triangles Relating Trigonometric Functions 1 Answer Nghi N. May 15, 2015 since on the trig unit circle: cos (2x + pi/2) = sin (2x), then y = -4sin (2x) + 1 Answer link Related questions What does it mean to find the sign of a trigonometric function and how do you find it? What are the reciprocal identities of trigonometric functions? What are the quotient identities for a trigonometric functions? What are the cofunction identities and reflection properties for trigonometric functions? What is the pythagorean identity? If sec theta = 4, how do you use the reciprocal identity to find cos theta? How do you find the domain and range of sine, cosine, and tangent? What quadrant does cot 325^@ lie in and what is the sign? How do you use use quotient identities to explain why the tangent and cotangent function have... How do you show that 1+tan^2 theta = sec ^2 theta? See all questions in Relating Trigonometric Functions Impact of this question 2292 views around the world You can reuse this answer Creative Commons License