Survey of MathSeminar, Unit 4

Tonight: Variation, Inequalities, and Coordinate Geometry

Math Quote of the Week:“The science of pure mathematics ... may claim to be the

most original creation of the human spirit.” –Alfred North Whitehead

Direct Variation

#26. r varies directly as the square of s. Determine r when s = 2 and k = 13

Henry’s law: P = HC

P is partial pressure, H is Henry’s constant, C is concentration of pollutant gas

Inverse Variation

Suppose H varies inversely to G.

If G is 12 and k is 4…

Joint Variation

Area of Triangle is A = ½ bh

What is area if b and h are 4 and 6 respectively?

Combined Variation

Darcy’s Law: Q = KAP/L

Q is flow, K is constant, A is area, L is length, and P is hydrostatic pressure difference

The Coordinate Grid

Quadrant 2 Quadrant 1

Quadrant 3 Quadrant 4

Graphing Linear EquationsGraph y = 2x – 3

x y pair

Graphing Linear EquationsGraph 4y + 6x = 12

x y pair

Slope

Slope = m = y2 – y1

x2 – x1

using points (x1,y1) and (x2,y2)

(-2,-4) and (3,7) slope, m =

Slope

#70 … our points are (-5, 6) and (8, 8)

Slope = m = y2 – y1

x2 – x1

Inequalities–9t + 6 > 16

Inequalities–9(h – 3) + 2h < 8(4 – h)

–9h +27 + 2h < 32 – 8h