Page:Calculus Made Easy.pdf/100

negative value; hence ${\frac {dy}{dx}}$will have negative sign also.

If the “curve” happens to be a straight line, like that in Fig. 12, the value of ${\frac {dy}{dx}}$ will be the same at all points along it. In other words its slope is constant.

Fig. 12.

If a curve is one that turns more upwards as it goes along to the right, the values of ${\frac {dy}{dx}}$ will become

Fig. 13.

greater and greater with the increasing steepness, as in Fig. 13.