Thread: a little help please

1. the angle A is standard position is defined in terms of the co-ordinates (x,y) of the terminal arm, and the radius r of the circle. the trigonometric functions of the angle A can be expressed in terms of x,y, and r. the expression r/x represents is?

2. how many solutions are there to the equation sin^2 x + sin x = 0 over the domain.

3. smallest positive angle that is equivalent to an angle of -2pi/3 is?

Originally Posted by ck3

1. the angle A is standard position is defined in terms of the co-ordinates (x,y) of the terminal arm, and the radius r of the circle. the trigonometric functions of the angle A can be expressed in terms of x,y, and r. the expression r/x represents is?

This is a bit difficult to understand, but I will assume it describes the
situation in the attachment.

Then sec(A)=r/x=1/cos(A).

RonL

Originally Posted by ck3

2. how many solutions are there to the equation sin^2 x + sin x = 0 over the domain.

I assume by the domain you mean [0,2pi), we seek the points at which
sin^2(x)=-sin(x). Plot these and count them. See attachment, I make
it 3 (as the fourth is at 2pi which is outside the domain).

3. smallest positive angle that is equivalent to an angle of -2pi/3 is?

the required positive angle is 2pi-2pi/3=4pi/3.

RonL