Question

Write the equation of the line having slope 2 and y-intercept −3 and hence find the area of the triangle formed by this line and the two coordinate axes.

Answer 1

We have m = 2 and c = −3. 

Therefore, the equation of the line is y =  2x - 3 . The line meets the axes at (3/2, 0) and (0, −3). Hence, the vertices of the triangle are (0, 0), (3/2, 0) and (0, −3).

Therefore, area of the triangle is

1/2|0(0 + 3) + 3/2(-3 - 0) + 0(0 - 0) = 9/4 sq. unit