Evaluate Composite Trig Functions

5. Inverse Trigonometric Functions and Basic Trigonometric Equations / Evaluate Composite Trig Functions / Problem 5

Determine the exact value of the following trigonometric expression by sketching.
tan [cos^-1 (-2/5)]

√(21)/2

-√(21)/2

-√(21)/5

√(21)/5

Determine the exact value of the following trigonometric expression by sketching.tan [cos-1 (-2/5)]