Wednesday, January 30, 2013

Graph of Y Square Root of X

Generally a function is described in the form y = f(x), y being the value the function at any general point x in the domain of the function. The letter y is chosen because the values of the function is represented by the y-axis in a graph.

The graph of the function gives a visual presentation of the function which helps us to study the function at a glance.

The values of square root of positive real numbers is expressed as function f(x) = square root of x or simply y = square root of x. The graph of y = square root of x is an interesting study and let us take a closer look.


Concept of a Square Root Function:

Consider a simple square function y = x2. It is a special  form of a quadratic function. We know that the graph of a quadratic function is a parabola. In this case it is a vertical, concave up parabola with origin as vertex. The graph is shown below.

graph y= x^2

Let see what is the inverse of the function y = x2

y = x2, or, √y = x and by interchanging the variable we get the inverse function as,

y = √x

Thus the square root function is nothing but the inverse of the square function.

We had seen that the graph of y = = x2 is symmetrical over y –axis. Therefore, the graph of y = square root of x has to be symmetrical over x-axis. However, since negative values of root of x have no meaning, the graph exists only in the first quadrant of the Cartesian system. It is shown below.

graph of y square root of x


Example Problems on Graph of Y Square Root of X

From the graph of y square root of x, find the value of square root 3 to the nearest tenths. (Assume the sale to be 1unit on both the axes)

graph of y square root of x

Since the scale of the graph is 1 unit each small division represents 0.2 unit. It is seen from the graph, when x = 5, the value of y is 1.7. Hence, square root of 3 is 1.7, nearest to tenths.

Use the graph of y square root of x, to evaluate 2( square root 6) to the nearest tenths. (Assume the sale to be 1unit on both the axes)

graph of y square root of x

Since the scale of the graph is 1 unit each small division represents 0.2 unit. It is seen from the graph, when x = 6, the value of y is 2.5. Hence, 2(square root of 6) = 2(2.5) = 5

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