Final answer:
When simplified, the expression is equivalent to approx. 0.5778, which is closest to the tangent of 30°.
Step-by-step explanation:
First, we will simplify the expression by substituting the given values of the angles:
tan(40°) - tan(10°) / (1 + tan(40°)tan(10°))
Next, we will calculate the values of the tangents:
tan(40°) = 0.8391
tan(10°) = 0.1763
Now, substitute the calculated values into the expression:
0.8391 - 0.1763 / (1 + 0.8391 * 0.1763)
Simplifying further:
0.8391 - 0.1763 / (1 + 0.1478)
Calculating the numerator:
0.6628 / 1.1478
Dividing, we get:
0.5778
Therefore, the expression is equivalent to approx. 0.5778, which is closest to the tangent of 30°, so the answer is c. tan(30°).