Algebra Flashcards
p(x) = (2m - 1)x² + (m + 1)x + (m - 4) can be written as a perfect square. Find the value of m.
- Find the value of a, b and c
- Write the equation in the form b² - 4ac = 0
- Simplify the equation into quadratic form
- Solve equation with a calculator to find the values of m
- Eliminate one solution, as the expression is a perfect square
By factorizing, find the expression in terms of p for the difference between the roots of the equation (px)² + 4px - 12 = 0
- Find the value of a, b and c
- Write the equation using the quadratic formula x = -b ± √b² - 4ac / 2a
- Simplify the equation to remove the square root
- Solve for if the equation is positive and negative
Show that the graph of the function y = (x - a)(x - b) - c², where c ≠ 0, crosses the x-axis at two distinct points.
- Expand brackets
- Factorise into the quadratic form
- Find the value of a, b and c
- Write the equation in the form b² - 4ac > 0
- Simplify the equation (add brackets and powers if necessary) to leave two terms
- Write the answer as ‘since (term 1) > 0 and (term 2) > 0, c ≠ 0
- Powers
- When multiplying terms, add the powers
- When dividing terms, subtract the powers
- When raising a term with a power to another power, multiply the powers
- Negative powers
Numbers
- With fractions, invert and raise each number to its positive power (simplify the fractions first if necessary)
Variables
- To change a - power to +, put the variable with the negative power on the bottom of the fraction
- Use brackets when more than 1 expression is being raised to a power
- Surds
Surd form = Index form
ᵃ√xᵇ = x b/a
- Convert the expression into index form
- Use power laws to simplify the expression (split the terms under the square root if necessary).
- Roots, powers and coefficients
- When raising a number/variable with a power to another power, use brackets, then simplify to remove the brackets
- Powers (base is a number)
- Rewrite the expression with the smallest base possible
2. Use the power laws to simplify the expression
- Logarithm rules
- log a + log b = log ab
- log a - log b = log a/b
- n log a = log aⁿ
- Rewrite the expression using the logarithm of the smallest number possible
- Simplify using the logarithm rules
- logᵦ 1 = 0
- logᵦ b = 1
- logᵦ(mn) = logᵦm + logᵦn
- logᵦ(m/n) = logᵦm - logᵦn
- logᵦmⁿ = nlogᵦm
- logᵦ(1/x) = -logᵦx
- Solving logarithm equations - Basic
- Rewrite logᵦ y = x as y = bˣ
2. Use calculator to find y
- Solving logarithm equations - Finding the base or exponent
- Rewrite logᵦ y = x as y = bˣ
2. Figure out value of b, then check on calculator
- Solving logarithm equations - Finding the exponent with messy numbers
- Take the log of both sides
- Use log rules to rearrange it > x log a = log b
- Divide other side of equation by log a to remove it > x = log b / log a
- Use calculator to find the value of x
- Applications of exponential equations
1. Rewrite in the form A = Prⁿ, where P = The starting value r = The rate of change n = The number of time periods (often years) over which change occurs A = The final amount
- Rates of change
- No change r = 1
- Increase r > 1
- Decrease r < 1
- Add/subtract percentage to/from 100 to determine rate of change. If it is an increase, add. If it is a decrease, subtract. Use (100 ± x / 100) - If asked to calculate n, take the log of both sides
- Fractions - Multiplying and dividing
- Multiplying fractions
a/b x c/d = ac/bd
- Dividing fractions
(Invert the second fraction and multiply)
a/b / c/d = ad/bc
- Fractions - Adding and subtracting
- With same denominator
a/b ± c/b = a±c/b
- With different denominator
Multiply both the numerator and denominators by a number or variable that will create equal denominators
a/b ± c/d = ad/bd ± bc/bd = ad ± bc/bd