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Cosine Is a Shifted Sine

Part of the Graphs of Trig Functions section of Coddy's Trigonometry journey. Lesson 6 of 49.

Most people think a plus inside the brackets moves a graph right. It moves it left. To draw the cosine, you moved the sine wave π/2 to the left. So cos⁡(x)=sin⁡(x+π2)\cos\left(x\right) = \sin\left(x+\frac{\pi}{2}\right).

The cosine reaches each height π/2 earlier than the sine. Earlier means further left on the graph. Adding inside the brackets moves a graph left. Subtracting moves it right.

The sine and cosine waves on one axis: the cosine is the sine moved pi over 2 to the left

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Challenge

Draw y=sin⁡(x+π4)y = \sin\left(x+\frac{\pi}{4}\right).

Then press Check.

Try it yourself

y=sin⁡(x+π4)y = \sin\left(x+\frac{\pi}{4}\right)

Draw the wave

All lessons in Graphs of Trig Functions