Graphs of Functions
Graphs of Functions
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Domain and range: The domain of a function is the set of all possible input values (x-values), while the range is the set of all possible output values (y-values).
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Function notation: Functions can be denoted with a letter of the alphabet followed by parentheses, e.g., f(x).
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Increasing and decreasing functions: If the y-value increases as the x-value increases, the function is increasing. If the y-value decreases as the x-value increases, the function is decreasing.
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Maximum and minimum points: A maximum point on a function is a point where the y-value is greater than the y-values of the points immediately to its left and right. A minimum point is where the y-value is smaller.
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Odd and even functions: An even function is symmetrical about the y-axis, while an odd function is symmetrical about the origin.
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Composite functions: Composite functions are functions composed of two or more simpler functions.
Modulus
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Definition: The modulus of a real number is its absolute value. It is always positive or zero.
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Properties: The modulus of a product is the product of the moduli, and the modulus of a quotient is the quotient of the moduli.
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Modulus equations: These equations involve the absolute value of a variable expression. Solution may involve squaring both sides or splitting the equation into two separate cases.
Cubics
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Degree of cubics: A cubic equation is one where the highest power of the variable is 3.
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Shape of cubic curves: All cubic curves have a single point of inflection. They can have either one or three roots.
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Roots of cubics: The roots of a cubic lie either on the x-axis (real roots) or off the x-axis (complex roots).
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Factorising cubics: Cubics can be factored into linear and quadratic terms by using synthetic division and the factor theorem.
Inequalities
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Interpreting inequalities: Inequalities describe the relative size of different values. This can be visualised on a number line.
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Solving inequalities: Solving inequalities often involves reasoning similar to solving equations, but the direction of the inequality sign must be preserved.
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Quadratic inequalities: Quadratic inequalities can be solved using factorisation or the quadratic formula, but remember to consider when the quadratic expression is positive or negative.
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Graphing inequalities: Inequality in two variables usually bound a region in the coordinate plane, which can be shaded or hatched on a graph.
Simultaneous Equations
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Methods of solving: Simultaneous equations can be solved by substitution, elimination, or graphical methods.
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Nonlinear simultaneous equations: These involve at least one non-linear equation and can typically be solved using substitution.
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Applications: Simultaneous equations are used in many real-world applications including finance, physics and geometry.