show y=3x-5 is tangent to x^2 + y^2 +2x -4y - 5 = 0 and the point where they touch
y=3x-5x^2 + (3x-5)^2 + 2x - 4(3x-5) - 5 = 0x^2 + 9x^2 -30x +25 + 2x -12x + 20 - 5 = 010x^2 -40x + 40 = 010 (x^2 - 4x +4) = 010(x - 2)^2 = 0x=2implies one point of contact, therefore tangenty = 3x - 5y = 6 -5 = 1
RM
Related Maths Scottish Highers answers
All answers ▸Describe an exponential function and the exponential decay equation.
PQR is a triangle with vertices P (−2, 4), Q(4, 0) and R (3, 6). Find the equation of the median through R.
If f(x) = 1/(6x^2), where x not equal to 0, find the rate of change when x=4.
A triangle has vertices A(-3,5), B(7,9) and C(2,11). What is the equation of the median that passes through the vertex C?