230 likes | 249 Views
Lesson 5- Geometry & Lines. Objectives : Quick recap on last weeks work Coordinate geometry definitions - Equations of straight lines - Intersection of lines (Simultaneous equations) Intersection of line and quadratic (solve by algebra)
E N D
Lesson 5- Geometry & Lines • Objectives : • Quick recap on last weeks work • Coordinate geometry definitions • - Equations of straight lines • - Intersection of lines (Simultaneous equations) • Intersection of line and quadratic (solve by algebra) • Intersection of line and quadratic (solve by graph) • Some types of curve INTO - Foundation L5 MH
Recap what we did last week • We quickly talked about: • Accuracy of numbers as defined by: • Decimal Places (dp) or Significant Differences (sf) • Irrational or Rational numbers • Rational numbers can be expressed as a fraction in its lowest for • iii. Rules of Indices INTO - Foundation L5 MH
Some definitions Circumference Radius Diameter • Collinear – points lie on a straight line • Parallel – going in the same direction • Quadrilateral – a shape with 4 sides • Triangle - a shape with 3 sides • Right angle - 90º • Right-angled triangle • Isosceles triangle – 2 sides the same length • Equilateral triangle – all sides the same length • Scalene triangle – all sides different lengths • Trapezium – 2 parallel sides • Parallelogram – pairs of parallel sides • Rhombus – parallelogram with all sides equal • Square –4 sides equal, all angles 90º • Rectangle – 4 sides, all angles 90º • Vertex, vertices – corner, corners • Diagonal – line joining opposite corners INTO - Foundation L5 MH
Definitions • Gradient • Midpoint • Length • Perpendicular • Perpendicular Bisector INTO - Foundation L5 MH
Gradient A(3,5) ∆y B(0,2) ∆x INTO - Foundation L5 MH
Midpoint of a line P(-10,8) dy Mid = (0,1) Q(10,-6) dx INTO - Foundation L5 MH
Length of line P(-10,8) dy Q(10,-6) dx INTO - Foundation L5 MH
Perpendicular Lines • Let • Gradient line1 = m1 • Gradient line2 = m2 • m1×m2 = -1 m2=-1/2 m1=2 m2 = -1/m1 INTO - Foundation L5 MH
Perpendicular Bisector Find Midpoint Find grad1 Find grad2 Plot line P(4,8) Q(-4,-8) INTO - Foundation L5 MH
Straight Line Graphs y 10 9 8 All straight line graphs are of the form y = mx + c 7 6 5 4 3 y intercept = 3 2 1 x 0 -10 1 2 3 4 5 6 7 9 10 -9 -8 -6 -4 -3 -2 8 -7 -5 -1 -1 -2 -3 -4 -5 -6 -7 -8 -9 -10 m gives the gradient of the line and c gives the y intercept. dy= 2 dx= 1 y = 2x + 3 The gradient is defined as the dy/dx
Straight Line Graphs y 10 9 8 All straight line graphs are of the form y = mx + c 7 6 5 4 3 y intercept = -4 2 1 x 0 -10 1 2 3 4 5 6 7 9 10 -9 -8 -6 -4 -3 -2 8 -7 -5 -1 -1 -2 -3 -4 -5 -6 -7 -8 -9 -10 m gives the gradient of the line and c gives the y intercept. dy= 3 y = 3x - 4 dx= 1 The gradient is defined as the dy/dx
Straight Line Graphs y 10 9 8 All straight line graphs are of the form y = mx + c 7 6 5 4 3 2 1 x 0 -10 1 2 3 4 5 6 7 9 10 -9 -8 -6 -4 -3 -2 8 -7 -5 -1 y intercept = 1 -1 -2 -3 -4 -5 -6 -7 -8 -9 -10 m gives the gradient of the line and c gives the y intercept. y = ½x + 1 dy= 1 dx= 2 The gradient is defined as the dy/dx
(b) (d) (a) (c) (e) Consider the straight lines shown below: Can you split the lines into two groups based on their gradients ? Positive gradient Lines (a) (c) and (d) slope upwards from left to right. Negative gradient Lines (b) and (e) slope downwards from left to right.
Straight Line Graphs y 10 9 8 All straight line graphs are of the form y = mx + c 7 y intercept = 3 6 5 4 3 2 1 x 0 -10 1 2 3 4 5 6 7 9 10 -9 -8 -6 -4 -3 -2 8 -7 -5 -1 -1 -2 -3 -4 -5 -6 -7 -8 -9 -10 m gives the gradient of the line and c gives the y intercept. dy= 4 dx= 5 The gradient is defined as the dy/dx
y Determine the equations of the following lines 10 9 1 5 8 7 6 5 2 4 4 3 2 1 x 0 -10 1 2 3 4 5 6 7 9 10 -9 -8 -6 -4 -3 -2 8 -7 -5 -1 -1 -2 -3 6 -4 -5 3 -6 -7 -8 -9 -10 • y = 2x + 3 • y = 3x – 5 • y = -x + 6 • Y = ½x –2 • Y = - 4x –9 • y = ¾x
Find equation of straight line Given points A(3,4) , B(-6,2) Find gradient (m) Find the equation of the line through AB
Point of Intersection Find the intersection point between the lines : y = 2x+3 y = -2x+1 C Answer C( -1/2 , 2 ) INTO - Foundation L5 MH
Points of Intersection Find the intersection point between the curve and the line : y = x2-2x-3 y = 2x-1 B Answer A(2-√6 , 3-2√6) B(2+√6, 3+2√6) A INTO - Foundation L5 MH
Progress ? • Objectives : • Quick recap on last lesson work • Coordinate geometry definitions • - Equations of straight lines • - Intersection of lines (Simultaneous equations) • Intersection of line and quadratic (solve by algebra) • Intersection of line and quadratic (solve by graph) • Some types of curve (**) INTO - Foundation L5 MH
Challenge Question • The line with equation 5x + y = 20 meets the x-axis at A and the line with equation x + 2y = 22 meets the y axis at B. • The two lines intersect (meet, cross) at point C. • sketch the two lines on the same diagram • calculate the co-ordinates of A, B, C • calculate the area of triangle OBC where O is the origin • find the coordinates of point E such that ABEC is a parallelogram INTO - Foundation L5 MH
A(4,0) B(0,11) C(Solve) C B O A Point C, solve simultaneously Area of OBC is 11 square units C(2,10) INTO - Foundation L5 MH
find the coordinates of point E such that ABEC is a parallelogram E C(2,10) E B(0,11) C B A(4,0) A E(-2,21) INTO - Foundation L5 MH
3 basic curve types INTO - Foundation L5 MH