Question

The lining joining (-1,1) and (2,-2)and the line joining (1,2) and(2,k) is perpendicular find the value of k?

Answer 1

the ans is k= 1........
by slope formula
-2-2/2-(-1)=k-2/2-1
-3/3=k-2/1
-3=3(k-2)
-3=3k-6
-3k=-6+3
-3k=-3
k=1

Answer 2

Answer:

k=3

Step-by-step explanation:

• using the slope formula: y2-y1 /x2-x1 = y2-y1 / x2-x1
• -2-1/2+1 = k-2/2-1
• -3 /3 = k-2 /1
• now take the reciprocal or 2nd term ( coz the r perp.)
• -1 = -1/k-2
• -k+ 2 = -1
• k=3