The tangent of an angle is the ratio of the
y -value to the
x -value of the corresponding point on the unit circle.
The secant, cotangent, and cosecant are all reciprocals of other functions. The secant is the reciprocal of the cosine function, the cotangent is the reciprocal of the tangent function, and the cosecant is the reciprocal of the sine function.
The six trigonometric functions can be found from a point on the unit circle. See
[link] .
Trigonometric functions can also be found from an angle. See
[link] .
Trigonometric functions of angles outside the first quadrant can be determined using reference angles. See
[link] .
A function is said to be even if
and odd if
Cosine and secant are even; sine, tangent, cosecant, and cotangent are odd.
Even and odd properties can be used to evaluate trigonometric functions. See
[link] .
The Pythagorean Identity makes it possible to find a cosine from a sine or a sine from a cosine.
Identities can be used to evaluate trigonometric functions. See
[link] and
[link] .
Fundamental identities such as the Pythagorean Identity can be manipulated algebraically to produce new identities. See
[link] .
The trigonometric functions repeat at regular intervals.
The period
of a repeating function
is the smallest interval such that
for any value of
The values of trigonometric functions of special angles can be found by mathematical analysis.
To evaluate trigonometric functions of other angles, we can use a calculator or computer software. See
[link] .
Section exercises
Verbal
On an interval of
can the sine and cosine values of a radian measure ever be equal? If so, where?
Yes, when the reference angle is
and the terminal side of the angle is in quadrants I and III. Thus, at
the sine and cosine values are equal.
Step 1: Find the mean. To find the mean, add up all the scores, then divide them by the number of scores. ...
Step 2: Find each score's deviation from the mean. ...
Step 3: Square each deviation from the mean. ...
Step 4: Find the sum of squares. ...
Step 5: Divide the sum of squares by n – 1 or N.
The sample of 16 students is taken. The average age in the sample was 22 years with astandard deviation of 6 years. Construct a 95% confidence interval for the age of the population.
Bhartdarshan' is an internet-based travel agency wherein customer can see videos of the cities they plant to visit. The number of hits daily is a normally distributed random variable with a mean of 10,000 and a standard deviation of 2,400
a. what is the probability of getting more than 12,000 hits?
b. what is the probability of getting fewer than 9,000 hits?
Bhartdarshan'is an internet-based travel agency wherein customer can see videos of the cities they plan to visit. The number of hits daily is a normally distributed random variable with a mean of 10,000 and a standard deviation of 2,400.
a. What is the probability of getting more than 12,000 hits