This study sheet has ten groups of trig identities for the basic trigonometry functions. These identities include the reciprocal and co-function relationships between trig functions. There are also half-angle and double angle identities, along with sum and product relationships. This table is an extremely useful thing to keep on hand when working with trig functions. Print a copy and keep it with your textbook today.

This cheat sheet is optimized to fit on a single sheet of paper. Download the PDF version to print your own.

theres a mistake at the product to sum: cosA*sinB= 1/2 *( sin(A+B) (! MINUS not plus !) sin(A-B) )

Only took two years for someone to point that out! ðŸ™‚

I’ve corrected the mistake and uploaded a new image and PDF. Thanks for catching that error!

theres a mistake, for the last sum/difference identity it should be tangent instead of cosine on the left side of the equation (i only mention it out of fear somebody else will get confused and write it down), thank you for this sheet though it helped a lot with my notes

Thanks for letting me know about the mistake. I’ve updated the PDF and the image to reflect the correction and a few minor cosmetic tweaks.