Expert: Ahmed Salami - 3/30/2009

Question
Hello Sir,

Am attending my MBA-HR examinations in May 2009 where in the paper Quantitative Analysis for Managerial applications is a compulsory subject.

Am really not so good at explaining graphs:  Could you help me to solve these problems with justifications?

a)  y=3x-5
B)  y = x2 (x square)
c)  y = log2x = logx / log 2

Answer
Hi Ashwini,
a)y = 3x - 5
at x = 0, y = -5
at y = 0, x = 5/3
This graph is a straigth line (its of the form y = mx + c) with x and y intercepts 5/3 and -5 respectively. The slope is positive and you would find in agreement with those values that it slopes upwards to the right.

b)y = x^2
at x = 0, y = 0
at y = 0, x = 0
This graph is a parabola (y = ax^2 + bx + c) concave upwards (because 'a' is positive) and with the tip at the origin.

c)y = log 2x = (log 2)(log x)
at x = 0, y doesnt exist becuase log 0 doesnt exist
at y = 0, x = 1 because log x = 0
This is the graph of log x amplified with a factor log 2. This curve never crosses the y axis.

You can check graph with http://www.coolmath.com/graphit/

Hope it helps you.

Regards