How do you use a calculator to approximate #arctan 2.8#?

1 Answer
Jan 31, 2017

#70.3°#

Explanation:

Arctan means you know the tan value and you want to know to which angle that tan value applies.

On most calculators, arctan is shown with the tan key 70.34617594° as # tan^-1#, which does NOT mean #1/"tan"#

You will probably need to use the 'shift/alt/2ndF' key to use it.

With a D.A.L. calculator, the key presses would be:

Shift #tan^-1 2.8 =#

The display will be #70.34617594# and is in degrees.

On older calculators you might need to press:

#2.8# shift #tan^-1#

The answer will be displayed without pressing =.