 Home > College of Sciences > Institute of Fundamental Sciences > Maths First > Online Maths Help > Trigonometry > Calculators and Trigonometric Functions SEARCH MASSEY  # Trigonometry

## Calculators and Trigonometric Functions

Calculators can be used to compute the values of trig functions at angles that are not necessarily special ( 0º, 30º = π/6, 45º = π/4, 60º = π/6, 90º = π/2).

Always make sure your calculator is set at the right mode (DEG or RAD)

Note: On some scientific calculators, to obtain the value of π you press the π key. On others, you press the EXP. Before continuing on, test your calculator to find which key gives you the value of π = 3.14159265359…

### Exercise

Use a calculator to compute the values of the trig functions at the given θ, where θ is measured in degrees.

 θ = º sin θ = 2 d.p. cos θ = 2 d.p. tan θ = 2 d.p. csc θ = 2 d.p. sec θ = 2 d.p. cot θ = 2 d.p.

### Exercise

Use a calculator to compute the values of the trig functions at the given θ, where θ is measured in radians.

 θ = radians sin θ = 2 d.p. cos θ = 2 d.p. tan θ = 2 d.p. csc θ = 2 d.p. sec θ = 2 d.p. cot θ = 2 d.p.

Note that for any x, If you are given the value of a trig function you can find the angle by using the inverse of the trig function. gives a value θ in such that  gives a value θ in such that  gives a value θ in such that Example

Find θ between and π so that sin θ = 0.3

By a calculator, This is in the first quadrant: To get the value in the second quadrant we calculate θ = π – 0.3047 =2.837

Exercise 6.

Find the angle θ (in radians), correct to 2-decimal places, in the interval specified with the given trig value. If there is no such angle type ND.

 Interval sin θ cos θ tan θ [ , ]