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Graphs of functions

Draw and read graphs on the coordinate plane, from single points and straight lines to powers and parabolas. Find where two graphs meet, shade the regions that inequalities describe, and graph curves written with xx as the subject.

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12

lessons

136

practice questions

13

prerequisite lessons

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2 of the 12 lessons here are free to preview - the whole explanation and worked example, with no account and no email.

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Lesson 04 · The equation of a straight line

12345−1−2−3−4−512345−1−2−3−4−5
x
y
(0,1)
Move the slider to change the slope m: every faint line has that slope. Drag the red point along the y-axis to pick out the line crossing at (0,c). The larger |m|, the steeper the line.
y=2x+1, with slope m=2 and y-intercept (0,1)

This is the diagram from the lesson itself, running here. Drag it - the lesson is built round the thing it shows, not round a picture of it.

The 12 lessons

The 12 lessons in this unit. Expand any one to see what it covers. Each unlocks when its own prerequisites are passed.

01

The coordinate plane

8 questions

Learn how to read the coordinates of a point marked on the coordinate plane, and how to plot a point from its coordinates.

Covers

Reading a point's coordinates

Plotting a point from its coordinates

02

The graph of an equation

13 questions

Learn how to decide whether a point lies on the graph of an equation, graph an equation by plotting a table of values, and read values off a graph.

Covers

Deciding whether a point is on a graph

Graphing an equation by plotting points

Reading values off a graph

03

The slope of a line

12 questions

Learn how to find the slope of a straight line from two of its points, read the sign and steepness of a slope from a picture, and see why horizontal lines have slope 00 and vertical lines have undefined slope.

Covers

Slope from two points

Reading slope from a picture

Slopes of horizontal and vertical lines

04

The equation of a straight line

Preview

12 questions

Learn how to read the slope and yy-intercept of a straight line from its equation in slope-intercept form, find the equation of a line drawn on a grid, and write the equations of horizontal and vertical lines.

Covers

The slope-intercept form

Finding the equation of a drawn line

The horizontal or vertical line through a point

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05

Point-slope form of a line

14 questions

Learn how to write the equation of the straight line through a point with a given slope in point-slope form, find the line through two points, and rewrite it in slope-intercept form.

Covers

The line through a point with a given slope

The line through two points

Converting to slope-intercept form

06

Graphs of power functions

12 questions

Learn the shapes of the square, cube and square-root curves, the symmetry behind each shape, and which curve is highest on either side of x=1x = 1.

Covers

The symmetries of y=x2y = x^2 and y=x3y = x^3

The curve of y=xy = \sqrt{x}

Comparing heights of the curves

07

Parabolas and their turning points

8 questions

Learn how to tell which way a parabola opens and where it crosses the yy-axis from its equation, and how to locate its turning point midway between the points where it crosses the xx-axis.

Covers

The parabola and which way it opens

Locating the turning point

08

Where two graphs meet

14 questions

Learn how to find where a parabola meets a line or another parabola by setting their equations equal and solving, and how to use the discriminant to count the points of intersection without solving.

Covers

The equation for the points of intersection

Finding the points of intersection

Counting points of intersection with the discriminant

09

Two-variable inequalities

12 questions

Learn how to shade the region where an inequality in two variables holds, on the correct side of its boundary line or curve, and how solid and dashed boundaries tell non-strict and strict inequalities apart.

Covers

Horizontal and vertical boundaries

Shading the region of an inequality

Solid and dashed boundaries

10

Regions where two conditions hold

10 questions

Learn how to pick out the region where two conditions in xx and yy both hold, find the smallest rectangle that contains a bounded region, and recognise when a region is unbounded.

Covers

The overlap of two regions

Bounded and unbounded regions

11

Describing planar regions

8 questions

Learn how to write a region of the plane as a set of points in set-builder notation, from half-planes and rectangles to regions bounded by curves, and how an equation gives a curve while an inequality gives a region.

Covers

A region as a set

Curves and regions as sets

12

Curves given as xx in terms of yy

Preview

13 questions

Learn how to graph equations that have xx as the subject, from straight lines to parabolas turned on their side, and how to rewrite a line or a parabola with the other variable as the subject, choosing the right sign for each branch.

Covers

Lines with xx as the subject

Sideways parabolas

The same curve written both ways

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Where this unit sits in the curriculum

This unit is part of our Mathematical Foundations for ML learning path, which contains 95 lessons. Every one of them is drawn below.

The diagnostic test lets you skip any lesson you already know, including the ones in this unit.

Every dot is a lesson and every line a prerequisite. The 12 red dots are the lessons in Graphs of functions; the 13 blue dots feeding into them are the lessons Graphs of functions depends on; the 70 pale dots are the rest of the learning path, which come after Graphs of functions or alongside it.Graphs of functionsFirst lessons on the left95 lessons

Hover any dot to name its lesson.

12 lessons in this unit

13 prerequisite lessons across the unit, counting every step back to the start

70 other lessons in the learning path - after this unit, or alongside it

Every dot is a lesson, every line a prerequisite. You can only start a lesson once you have mastered all of its prerequisites, so you are always building on solid foundations.

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More in Mathematical foundations: Inequalities and absolute value, Quadratic equations, Set operations, Exponents and roots, Functions, Summation, product, and indexed notation, Logic, Exponentials and logarithms, Trigonometry