Trigonometric identities
Types of exercises: sine, cosine and tangent together, the Pythagorean identity, the identities for an obtuse angle, value of an expression with sine and cosine.
Exercises are drawn at random from a large bank - every click gives a different set.
Narrow the topic
Solved: 0 of 10
Compute the sine of the obtuse angle α
cos α = −1/3
The angle α is acute. Find the value of the expression
(2sin α + 3cos α)/(3sin α + 3cos α), if tan α = 1/3
Compute the tangent of the obtuse angle α
sin α = 21/29, cos α = −20/29
Compute the cosine of the obtuse angle α
sin α = 16/65
Give the measure of the obtuse angle α
tan α = −√3/3
The angle α is acute. Find the cosine of the angle α
3tan α = 8sin α
Compute the sine of the obtuse angle α
tan α = −12/5, cos α = −5/13
Compute the sine of the acute angle α
cos α = 21/29
Compute the tangent of the obtuse angle α
cos α = −√77/9
The angle α is acute. Find the value of the expression
(sin α − cos α)², if sin α · cos α = 1/3
This address is one particular set - everyone who opens it gets exactly the same exercises. Copy the link from the address bar and send it to the class. You can generate a new set at the top of the page.
PhiBoard is a free online whiteboard for maths
These exercises are part of it. On the board itself you can plot a function, write a formula in LaTeX, or solve a problem together with a teacher or a friend - live, in the browser. Our app is completely free.