Question

The straight line ax+by+c=0 where abc is not equal to zero will pass through the first quadrant if (a)ac>0,bc>0 (b)ac>0 and bc<0 (c)bc>0 or ac>0 (d)ac<0 and / or bc<0

Answer 1

ax+by+c = 0

Change this equation into the intercept form.
=>   x/ (-c/a)   +  y / (-c/b)   = 1

x intercept = -c/a         y intercept = - c/b

if the straight line passes through first quadrant, then both x-intercept and y-intercept should not be negative simultaneously, in which case the line lies in 3rd quad, 2 nd quad and 4 th quad only.

ac > 0 and  bc> 0 => both intercepts are negative...so in 3rd quad.

ac > 0 and  bc < 0 => x intercepts negative, y intercept is positive. So the line is in 1st quad, 2nd and 3 quadrants.

bc > 0 or ac>0     => x intercept is negative OR y intercept is negative.  This will lie in the first quad. and also in other quadrants.

Answer 2

Answer:

I hope it helps you..........