Understanding Trigonometric Transformations: Analyzing a Horizontal Translation

[aisha]

$$y=2\cos (\frac {-1} {2}x + 90 ) -3$$

I changed the original function to

$$y=2\cos [\frac {-1} {2} (x-180)] -3$$

period=-4pi
amplitude=2
max=-1
min=-5
range={y:-5<=y<=-1}
domain={x:XER}
vertical displacement 3 units down
horizontal translation 180 units left

 

[HallsofIvy]

We can't tell- there is no "x" in the original function.

 

[iNCREDiBLE]

aisha: do not confuse radians and degrees.

 

[aisha]

I don't think I am confused about radians and degrees some of my trig functions have radians in them so to make things simpler I convert to degrees but in this question i haven't done any converting that 90 is in degrees.
sorry I added the x in the original function.

 

[aisha]

Did i do this question correctly?

 

[TD]

Yes, seems correct although I think the horizontal displacement is to the right.

 

[LeonhardEuler]

If the original question had 90 in it, then you did it correctly except for the direction of the horizontal translation. If the original question had $\frac{\pi}{2}$ in it, then the value of the horizontal translation is off too.

 

[aisha]

thanks so much the original question does have 90 degrees in it. You are right the horizontal translation should be to the right NOT LEFT!