UK Secondary (7-11) Amplitude of sine and cosine

## Interactive practice questions

How does the graph of $y=3\cos x$y=3cosx differ from the graph of $y=\cos x$y=cosx?

Select all the correct options.

The amplitude of $y=3\cos x$y=3cosx is $3$3 times greater than the amplitude of $y=\cos x$y=cosx.

A

The period of $y=3\cos x$y=3cosx is greater than the period of $y=\cos x$y=cosx.

B

The maximum value of $y=3\cos x$y=3cosx is $3$3 times greater than the maximum value of $y=\cos x$y=cosx.

C

$y=3\cos x$y=3cosx is a reflection of $y=\cos x$y=cosx about the $x$x-axis.

D

The amplitude of $y=3\cos x$y=3cosx is $3$3 times greater than the amplitude of $y=\cos x$y=cosx.

A

The period of $y=3\cos x$y=3cosx is greater than the period of $y=\cos x$y=cosx.

B

The maximum value of $y=3\cos x$y=3cosx is $3$3 times greater than the maximum value of $y=\cos x$y=cosx.

C

$y=3\cos x$y=3cosx is a reflection of $y=\cos x$y=cosx about the $x$x-axis.

D
Easy
Approx a minute
Consider the graph of $y=\cos x$y=cosx, shown below. Use the characteristics of this graph to state the amplitude of $y=4\cos x$y=4cosx.
Determine the equation of the graphed function given that it is of the form $y=a\sin x$y=asinx or $y=a\cos x$y=acosx, where $x$x is in degrees.
Determine the equation of the graphed function given that it is of the form $y=a\sin x$y=asinx or $y=a\cos x$y=acosx, where $x$x is in degrees.