Question 11
Question: The vertices of a triangle are (0,0), (a, b) and (b, -a), find the equation to the sides of the triangle.
Answer: Let O (0,0), A (a, b) and B (b, -a) be the vertices of the triangle OAB.
ay = bx or bx - ay = 0
Equation of side OB is
by = -ax
ax + by = 0
Equation of the side AB is
Question 12
Question: Find the equation of the line through A (3,0) and B (0, -3).
Answer: Let P (x, y) be any point on the line joining A and B.
\ Equation of line is
Question 13
Question: Reduce each of the following straight line equation to the slope-intercept form. Find m and c.
Answer: The slope-intercept form of the equation of line is y = mx + c.
Question 14
Question: Find the equation of the line through (1,2) and parallel to x + 3y = 1.
Answer: Given line is x + 3y = 1.
The line passes through (1,2).
Let P (x, y) be any point on the required line.
Aliter:
The line parallel to x + 3y - 1 = 0 is x + 3y = k.
This line passes through (1,2).
Putting x = 1 and y = 2 in x + 3y = k, we have
The equation of the required line is x + 3y = 7.
Question 15
Question: Find the equation of the line with y-intercept 7 and parallel to
4x + 5y = 8.
Answer: Reduce the equation to y = mx + c form .
But c = 7,
