I presume you want the points where the circle x2 + y2 + 4x + 6y - 40 = 0 and the line x - y = 10 meet.
x - y = 10
=> y = x - 10
Substitute into circle equation:
x2 + y2 + 4x + 6y - 40 = 0
=> x2 + (x - 10)2 + 4x + 6(x - 10) - 40 = 0
=> x2 + x2 - 20x + 100 + 4x + 6x - 60 - 40 = 0
=> 2x2 - 10x = 0
=> 2x(x - 5) = 0
=> x = 0 or 5
=> y = -10 or -5 respectively
The line meets the circle at the points (0, -10) and (5, -5).
Another method with the same result:
Equation 1: x2+y2+4x+6y-40 = 0
Equation 2: x-y = 10 => x = 10+y
Substitute Equation 2 into Equation 1:
(10+y)(10+y)+y2+4(10+y)+6y-40 = 0
100+20y+y2+y2+40+4y+6y-40 = 0
Collect like terms:
2y2+30y+100 = 0 => (2y+20)(y+5) = 0
y = -10 or y = -5
Substitute the above values into Equation 2:
When y = -10, x = 0
When y = -5, x = 5
Therefore the coordinates are: (0,-1) and (5,-5)
Coordinates: (-1, 5) and (6, 40) Length of line: 7 times the square root of 26 which is 35.693 to 3 d.p.
Average the x and y (and z if there is one) coordinates to find a midpoint of a line.
A tangent is a line that just touches a curve at a single point and its gradient equals the rate of change of the curve at that point.
If you mean a line of y = 2x+5/4 and a curve of y^2 = 10x Then it works out that the line touches the curve at: (5/8, 5/2)
-2
If you mean the coordinates of the line x-y = 2 that intersects the curve of x2-4y2 = 5 Then the coordinates work out as: (3, 1) and (7/3, 1/3)
Coordinates: (-1, 5) and (6, 40) Length of line: 7 times the square root of 26 which is 35.693 to 3 d.p.
Average the x and y (and z if there is one) coordinates to find a midpoint of a line.
Y Equals X PointsAll points that has the same y coordinates as x coordinates are on the y=x line.
A tangent is a line that just touches a curve at a single point and its gradient equals the rate of change of the curve at that point.
If you mean a line of y = 2x+5/4 and a curve of y^2 = 10x Then it works out that the line touches the curve at: (5/8, 5/2)
It is (-0.3, 0.1)
-2
For example, the equation of a line: y = ax + b. the equation of a curve: y = cx2 + dx + e ax + b = cx2 + dx + e (solve for x)
Combine the equations together and using the quadratic equation formula it works out that the point of contact is at (5/8, 5/2)
-4x + 9y = 0 is the equation of a line in the Cartesian plane and the coordinates of any of the infinite number of points on that line will satisfy the equation.
Combine the two equations together to give a quadratic equation in the form of:- 4x2 - 5x + 25/16 = 0 The solution to this is x = 5/8 or x = 5/8 meaning that it has equal roots therefore the line is tangent to the curve. The discriminant of b2 - 4ac = 0 also proves that the quadratic equation has two equal roots which makes the line tangent to the curve. Further proof can be found by plotting the straight line and curve graphically.