Question

The equation ax + by + c = 0 represents a straight line

Options

• for all real numbers a, band c

• only when b ≠ 0

• only when a ≠ 0

• only when at least one of a and b is non-zero

Answer 1

only when at least one of a and b is non-zero

Explanation:

When a = 0 then y = `(-c)/b` represents equation of straight the parallel to x – axis when b = 0 then x = `(-c)/a` represents equation of straight line parallel to y – axis. Hence, the equation ax + by + c = 0 represents a straight line only when at least one of a and b is non-zero.