Now you know that tan x = 3 or −2. Since x is a positive acute angle, the tangent is positive, and tan x
= 3. Now’s the time to use your calculator. You want to know what acute angle has a tangent of 3. In
other words, what you’re looking for is the arctangent of 3. Nobody expects you to know the value of
arctan (3) off the top of your head. Use your calculator:
The answer is (C).
In the next example, a calculator is not required, but knowledge of certain operations could save
you time.
Given the table below, which function represents the values in the table?x y
1 —1
3 5
5 11
7 17
9 234.
(A) y = 2x − 3
(B) x = 3y − 4
(C) x = 2y − 3
(D) y = 3x − 4
(E) y = x − 2