Zusammenfassung der Ressource
C1
- Simultaneous Equations & Disguised Quadratics
- Linear
- Add/ subtract the two equations
to eliminate one variable
- Set one equal to y or x and
substitute in
- Quadratic
- Substitution
- Disguised Quadratics
- Some equations- eg x^4-x^2-5=0 can be converted to quadratic
equations to solve more easily
- If there are three orders, ie x^4, x^2, x^0
- let A = the middle order, therefore
highest order = A^2
- Quadratics
- eg 4x^2+3x+7=0
- Solving
- If the equation factorises
- Each bracket = 0
- eg.(4x+3)(x-2)=0
- x = -3/4 or x = 2
- If does not factorise...
- Quadratic formula
- x= (-b ± √(b^2-4ac) ) / 2a
- Complete the square
- x^2 ± bx = (x±b/2)^2 - (b/2)^2
- Rearrange to find one or two values of x
- a(x+b)^2 + c
- Vertex = (-b, c )
- Inequalities
- If multiplying or dividing by a negative number, REVERSE the sign
- Quadratic
- Set so that equation = 0
- Factorise
- If equation > 0 it is where the graph is above the x axis
- If equation < 0 it is where the graph is below the x axis
- Intersections of lines
- Set equal to eachother to eliminate y
- Remember to get the y values at the end by re-substituting the x values
- Gradients, tangents and normals
- To find a gradient, differentiate the equation and then substitute in the x value
- The tangent to a curve has the same gradient as the point on the curve it touches
- y+y-value= m (x + x-value)
- Stationary points
- when dy/dx = 0
- solve dy/dx=0 to find stationary points
- Differentiate dy/dx to give d^2y/dx^2 .
Substitute in x values, if negative then it
is a max point, if positive it is a min point
- Coordinate Geometry, Lines and Circles
- Midpoints, gradients and distance between two points
- Point A => (x,y) Point B => (w,z)
- midpoint = ( (x+w)/2 , (y+z)/2 )
- length of the line through AB = √{ (x+w)^2 + (y+z)^2 }
- Gradient = (x-w)/(y-z)
- equation of a line through (a,b) with gradient m is y-b = m(x-a)
- Circles
- Equation of a circle centre (a,b) radius r = (x-a)^2 + (x-b)^2 = r^2
- Surds and indices
- Surds
- √m x √n = √mn
- √m / √n = √(m/n)
- To simplify k/√a multiply by √a / √a
- Indices
- a^(-n) = 1/(a^n)
- a^n x a^m = a^(m+n)
- a^m / a^n = a^(m-n)
- (a^m)^n = a^(m x n)
- a^0 = 1
- a ^ (1/n) = n√a
- a^ (m/n) = n√a^m
- Curve sketching and transformations
- any graph of the form y=x^n pass through (0,0) and (1,1)
- y=f(x)
- y=f(x) + a is a transformation a units upwards
- y=f(x+a) is a transformation -a units to the right
- y = f(ax) is a stretch sf 1/a parallel to x axis
- y = af(x) is a stretch sf a parallel to y axis