Q. What is the value of tan(225∘)?Choose 1 answer:(A) −1(B) −22(C) 22(D) 1
Understanding the tangent function: Understand the trigonometric function of tangent.The tangent of an angle in a right triangle is the ratio of the length of the opposite side to the length of the adjacent side, i.e., tan(θ)=adjacentopposite.
Recognizing the angle in the third quadrant: Recognize the angle 225∘ is in the third quadrant.Angles between 180∘ and 270∘ lie in the third quadrant, where both sine and cosine are negative, and therefore tangent (which is sine divided by cosine) is positive.
Finding the reference angle: Find the reference angle for 225∘.The reference angle is the acute angle that the terminal side of the given angle makes with the x-axis. For 225∘, the reference angle is 225∘−180∘=45∘.
Using the reference angle to find the tangent: Use the reference angle to find the value of tangent.The tangent of any angle is equal to the tangent of its reference angle, but with the sign that corresponds to the quadrant the original angle is in. Since 225∘ is in the third quadrant where tangent is positive, and the tangent of 45∘ is 1, the tangent of 225∘ is also 1, but with a negative sign due to the third quadrant's properties.
Choosing the correct answer: Choose the correct answer.The value of tan(225∘) is −1, which corresponds to answer choice (A) −1.