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VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Mathematical Methods CAS => Topic started by: lunapie on October 16, 2013, 09:12:57 pm

Title: methods 3/4 tranformation question
Post by: lunapie on October 16, 2013, 09:12:57 pm: I'm having a lot of trouble with transformations :(

f(x)= 6sin( $pi x / 2)$ and h(x) 6cos( $pi x / 2)$ ) ( Thats pi multiplied by x)

how do i get from f(x) to g(x)

thanks
Title: Re: methods 3/4 tranformation question
Post by: shadows on October 16, 2013, 09:31:43 pm: Try think about it graphically. Shift 1/4 period to the negative direction of the x axis, and your sin graph will look like a cos graph.

I hope that makes sense.
Title: Re: methods 3/4 tranformation question
Post by: b^3 on October 16, 2013, 09:34:14 pm: You can get a cosine curve by translating a sine curve (with the same argument, i.e. the same thing in the brackets), by translating the sine curve a quarter of a period to the left.
That is $\sin \left(x+\frac{\pi}{2} \right)=\cos(x)$ .
So work out the period (hint $\frac{2\pi}{n}$ where in this case $n=\frac{\pi}{2}$ ) and then divide by 4, that is your translation to the left.

EDIT: Beaten.