The tangent to 2x3 - 3x2 - 8x + 9 at x = 2 is y = 4x - 11
The tangent to y = 2x3 - 3x2 - 8x + 9 at x = 2 has the same gradient as the curve at that point; to find the gradient, differentiate:
dy/dx = 6x2 - 6x - 8
which at x = 2 is:
gradient = 6 x 22 - 6 x 2 - 8 = 4
At x = 2, y = 2 x 23 - 3 x 22 - 8 x 2 + 9 = -3
The equation of a line through point (xo, yo) with gradient m is:
y - yo = m(x - xo)
Thus the equation of the tangent to the line at x = 2 is:
y - -3 = 4(x - 2)
⇒ y = 4x - 11
-2
A linear equation.
It is an equation of a straight line.
Equation of circle: x^2 +y^2 -6x +4y +5 = 0 Completing the squares: (x-3)^2 +(y+2)^2 = 8 Radius of circle: square root of 8 Center of circle: (3, -2) Circle makes contact with the x axis at: (1, 0) and (5, 0) Slope of 1st tangent: 1 Slope of 2nd tangent: -1 1st tangent line equation: y = 1(x-1) => y = x-1 2nd tangent line equation: y = -1(x-5) => y = -x+5
3d + 14 = 11 is the equation.
(a) y = -3x + 1
Circle equation: x^2 +y^2 -8x +4y = 30 Tangent line equation: y = x+4 Centre of circle: (4, -2) Slope of radius: -1 Radius equation: y--2 = -1(x-4) => y = -x+2 Note that this proves that tangent of a circle is always at right angles to its radius
Equation of circle: x^2 +10x +y^2 -2y -39 = 0 Completing the squares: (x+5)^2 +(y-1)^2 = 65 Center of circle: (-5, 1) Point of contact: (3, 2) Slope of radius: 1/8 Slope of tangent: -8 Tangent equation: y-2 = -8(x-3) => y = -8x+26
Circle equation: x^2 +y^2 +6x -10y = 0 Completing the squares: (x +3)^2 +(y -5)^2 = 34 Center of circle: (-3, 5) Point of contact: (0, 0) Slope of radius: -5/3 Slope of tangent line: 3/5 Tangent line equation: y = 0.6x
A quadratic equation.
2
That's the equation.
k = 0.1
x = 0 and y = 4
equation 1: y = x-4 => y2 = x2-8x+16 when both sides are squared equation 2: x2+y2 = 8 Substitute equation 1 into equation 2: x2+x2-8x+16 = 8 => 2x2-8x+8 = 0 If the discriminant of the above quadratic equation is zero then this is proof that the line is tangent to the curve: The discriminant: b2-4ac = (-8)2-4*2*8 = 0 Therefore the discriminant is equal to zero thus proving that the line is tangent to the curve.
The summary equation is the formula equation. Sugar equals alcohol plus carbon dioxide. The formula is C6H12O6 which equals 2 CH3CH2OH plus 2 CO2.
The tangent equation that touches the circle 2x^2 +2y^2 -8x -5y -1 = 0 at the point of (1, -1) works out in its general form as: 4x +9y +5 = 0