Question 924266
by stretching vertically by a factor of {{{3}}}, and stretching horizontally to twice the length of the basic arccosine graph


Here's the graphs:


{{{ graph( 600, 600, -10, 10, -10, 10, cos^-1(x),3cos^-1(x/2) ) }}}

red line: {{{y = arccos(x)}}} or {{{y = cos^-1(x)}}}

green line: {{{g(x) = 3arccos(x/2) }}} or {{{g(x) = 3cos^-1(x/2) }}}