Question 486694
they are travelling at right angles to each other.
At any given instant they form a right triangle with their starting point

speed of one = x
 other = x+100

using Pythagoras theorem
x^2+(x+100)^2 = 1500^2
x^2+x^2+200x+10000=2250000

2x^2+200x-2240000

Find the roots of the equation by quadratic formula							
							
a=	2	,b=	200	,c=	-2240000		
							
b^2-4ac=	40000	-	17920000				
b^2-4ac=	17960000
{{{sqrt(	17960000	)}}}=	4237.92
{{{x=(-b+-sqrt(b^2-4ac))/(2a)}}}							
{{{x1=(-b+sqrt(b^2-4ac))/(2a)}}}							
x1=(	-200	+	4237.92	)/	4		
x1=	1009.48						
x2=(	-200	-4237.92	) /	4			
x2= 	-1109.48						
Ignore negative value							
1009.48	mph=	speed		of one plane 

add 100 to this speed to get speed of other
m.ananth@hotmail.ca