Question

Quick trig question!! Which equation represents the graph of y = cos x flipped across the x-axis then shifted vertically up by 2 units?


y = -cos x + 2

y = -cos x - 2

y = cos(x - 2)

y = cos(-x) + 2

Answer 1

I think it's the last option?

Answer 2

y = -cos x + 2. When you flip it, the amplitude changes from 1 to -1, thus turning all y-values to -y values. Then you shift it up 2, which is +2 at the end.

Answer 3

The first one

Answer 4

You were close, though :)

Answer 5

cool

Answer 6

hey could you help me with one last question?

Answer 7

Sure, what is it?

Answer 8

What is the period of the sinusoid given by y = -2sin (2pi/7 x)?

Answer 9

The period of a sinusoid function is 2pi divided by the coefficient of x, which is 2pi/7 in this case. So the period here would be 2pi/(2pi/7). That becomes 2pi*(7/2pi), which simplifies to 7.

Answer 10

So, the period is 7.

Answer 11

awesome!

Answer 12

You're welcome in advance

Answer 13

:)

Answer 14

oops forgot the second part to it :/ What is the amplitude of the sinusoid given by y=-4cos(2x)?

Answer 15

would it be -4?

Answer 16

just 4. The amplitude of a sinusoidal function, y = a*sin or cos(bx - c) is the absolute value of a. In this case a is -4, and the absolute value of -4 is 4.

Answer 17

awesome now I'm done thank you so much!!!