Monday

July 28, 2014

July 28, 2014

Posted by **Cassie** on Saturday, April 9, 2011 at 3:03pm.

sin (theta - pi/6)

b. Find the exact value of

cos (theta - pi/4)

c. For what numbers x, -2pi less than or equal to x less than or equal to 2pi does cos x = -1

d. What is the range of the cosine function?

e. For what numbers x, -pi less than or equal to x less than or equal to pi is the graph of y = cos x increasing?

f. Given: tan alpha = -4/3,

pi/2 < alpha , pi and

cos beta = 1/2, 3pi/2 < beta , 2 pi.

Find: tan (alpha-beta)

- Trigonometry -
**Anonymous**, Saturday, April 9, 2011 at 11:03pma.

sin(-theta)= -sin(theta)

sin(-pi/6)= - sin(pi/6)= -1/2

b.

cos(-theta)=cos(theta)

cos(-pi/6)=cos(pi/6)= sqroot(3)/2

c.

-pi

d.

The cosine function, like all of the trigonometric functions, is periodic about the rotation around a circle. Since the cosine is defined as the adjacent/hypotenuse of a right triangle, you can clearly see that its value can never be greater than one or less than -1 since the hypotenuse is always longer than the adjacent side. It turns out that, indeed, the cosine's range is from -1 to 1, written [-1,1].

e.

-pi/2,pi

**Related Questions**

Trig - 1. Establish the identity: sin(theta+3pi/2)=-cos(theta) 2. Find the exact...

Algebra II - Multiple Choice (theta) means the symbol 0 with the dash in it. 1.)...

Math- Trig - 1. Determine the exact value of cos^-1 (pi/2). Give number and ...

Pre-Calculus-check answers - If cos theta = 0.8 and 270<theta<360, find ...

easy trig - If sin(theta)=[sqrt(70)]/7 and theta is in Quadrant two, find the ...

simple trig - If sin(theta)=[sqrt(70)]/7 and theta is in Quadrant two, find the ...

Precalculus check answers help! - 1.) Find an expression equivalent to sec theta...

Precalculus check answers help! - 1.) Find an expression equivalent to sec theta...

Trigonometry - Thank you STEVE!!!!! Suppose that Cos (theta) = 1/square root 2 ...

Math - 1. Let (-7, 4) be a point on the terminal side of (theta). Find the exact...