Find the decimal value of a trigonometric function

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Pre-Calculus › Find the decimal value of a trigonometric function

Questions 1 - 5

Find the decimal value of

$2\cos\left(\frac{\pi}{6}\right)$

Explanation

To determine the decimal value of the following trig function, $2cos(\frac{\pi}{6})$ , make sure that the calculator is in radian mode.

Compute the expression.

$2cos(\frac{\pi}{6})=2(0.866)=1.732$

Determine the value of $cot(\frac{\pi}{3})$ in decimal form.

Explanation

Ensure the calculator is in radian mode since the expression shows the angle in terms of $\pi$ . Also convert cotangent to tangent.

$cot(\frac{\pi}{3})=\frac{1}{tan(\frac{\pi}{3})}= \frac{1}{\sqrt3}=0.577$

Find the value of

$\sin(270^\circ)+\cos(60^\circ)$ .

Explanation

Before beginning this problem on a calculator, though this is not necessary since these are special angles, ensure that the mode of the calculator is in degrees.

Input the values of the expression and solve.

Determine the correct value of

$sin\left(\frac{1}{2}^{\circ}\right)$ .

Explanation

The question $sin(\frac{1}{2})$ asks for the y-coordinate on the unit circle when the degree angle is $\frac{1}{2}$ .

Be careful not to confuse finding the value of the angle when the y-value of the coordinate of the unit circle is $\frac{1}{2}$ .

Ensure that the calculator is in degree mode.

$sin(\frac{1}{2})=0.00872=0.009$

Find the value of to the nearest tenth if and .

Explanation

Rewrite in terms of sine and cosine.

$cot(30)+tan(30)=\frac{cos(30)}{sin(30)}+\frac{sin(30)}{cos(30)}$

Substitute the known values and evaluate.

$\frac{0.866}{0.5}+\frac{0.5}{0.866}=1.732+0.577367 =2.309367$

The answer to the nearest tenth is .

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