# What are common mistakes students make with sinusoidal graphs?

##### 1 Answer
Jul 17, 2016

See the explanation.

#### Explanation:

T give importance to actual dimensions of the wave, without any

distortion due to use of both degree and radian measures for x. For

research problems in propagation of waves in Fluid Mechanics, this

is important. .

1. Graduations for y = sin x:

Always, keep x in radian units. $\pi r a \mathrm{di} a n = {180}^{o}$.

If 1 cm represents 1 unit of y on the y-axis,

The same 1 cm should represent 1 radian, on the x-axis. $\pi$ is

marked at 3.14 cm, from the origin.

1. One full wave for the period $2 \pi$ is the minimum span for the

graph. For the short Table (using pi=3.14, nearly)

$\left(x . y\right) : \left(0 , 0\right) \left(.0 .79 , 0.71\right) \left(1.57 , 1\right) \left(2.36\right) \left(3.14 . 0\right)$

$\left(3.93 , - .79\right) \left(4.71 , - 1\right) \left(6.28 , 0\right)$.

1. Degree equivalents for radian can appear, just below radian

graduations on the x-axis, for the Table in (2) above as

x: 0 45^o 90^o 135^o 180^o 225^0 270^0 315^o 360^o
.