Day 12 Weekend HW Assignment #1: ~45min. Assignment #2: ~45min. shall follow. 1. <10min. Basic graphing Review Some graphing tips – study if you CARE enough… NOTES A. You must master the graphs of parent functions: y = x2, y = x3, y = √x = x½, y = 3√x = x1/3, y = |x| y = 1/x y = 1/x2 y = log x y = ln x y = ax [growth and decay] y = ex y = sin x y = cos x y = x2/3 [the graph with a cusp] NOTES B. You must master the effects of simply transformations to f(x): Understand, dont memorize! y = af(x) → makes the graph rise faster [a > 1] or slower [0 < a < 1] than the parent function y = f(x ± a) → shifts the graph a units left / right y = f(x) ± a → shifts the graph a units up / down y = -f(x) → reflects the graph about the x-axis [flips it upside down] y = f(-x) → reflects the graph about the y-axis [left- and right- potions swap] y = f(|x|) → left potion of the graph is the same as the right, since the “heights” on the negative axis are the same as that on the positive ~ whatever’s on the right is what we have on the left y = |f(x)| → all negative heights, if any, turn positive...and get flipped upwards Plot all graphs on separate axes: copy the Q so I can do a quick assessment. a) -3x + 4y = 8 a’ y = -2/x b) y = ½ (x + 1)2 – 2 b’ y = 4/x c) y = 5(x – 1)3 + 3 c’ y = 7/x2 d) y = ½|x + 3| – 1 d’ y = -1/x2 e) y = 4(x + 1)(x – 6) e’ y = -√x + 2 f) y = -2·4x – 1 (Show asymptote) f’ y = 3√x + 4 g) y = 3x2 – 1 g’ y = -2x2 h) y = ln (x + 2) (Show asymptote) h’ y = x2 – 4x i) y = – ex – 1 (Show asymptote) i’ y = -3√x j) y = – ½x j’ y = -2x1/3 k) y = 4-x + 2 (Show asymptote) k’ y = x2/3 l) y = -log(x – 2) (Show asymptote) l’ y = x5/3 m) y = -5ex + 1 (Show asymptote) m’ y = -2x4/3 n) y = –ln x + 2 (Show asymptote) n’ y = -sin x o) y = 3 cos 2x o’ y = –log (-x) (Show asymptote) p) y = ln (-x) (Show asymptote) p’ y = ln (x – 1) (Show asymptote) q) y = sin |x| q’ y = ¼|x| + 2 r) y = | ln x | r’ y = | x2 + 3x| s) y = |cos x| s’ y = e|x| t) y = √-x t’ y = |3√x| u) y = | sin x| u’ y = ln |x| 2. <10min. Solving Exponential, Logarithmic and Trigonometric Equations Review Some equation-solving tips – study if you CARE enough… NOTES If youre in log form, go to expo form…and vice versa When solving trig equations, use x-y-r formulas 1st to determine if a triangle can be formed…since the angle might simply lie on the quadrant Quadrant angle equations might yield 1 or 2 answers; triangle equations always yield 2 answers. 30-60-90 triangle ratios are 1-√3-2 and 45-45-90 triangle ratios are 1:1:√2 Use All-Students-Take-Calculus to determine which quadrants work Adjust for the sign of the quadrant when writing ratios Copy the Q so I can do a quick assessment: use RADIAN MODE. a) e½x = 10 b) ln 3x = -1 c) 25x = 16 d) 10x – 2 = 4 e) log (2x – 3) = 13 f) sin θ = -½ g) cos θ = -1 h) tan θ = -1 i) sin θ = -√3/2 j) sin θ = 1 3. <10min. Solving inequalities…using the Number-Line trick! Some Domain-solving tips – study if you CARE enough… Polynomial function D: ALL real numbers since there are no breaks [Even-] Radical function e√m D: set m > 0 since m must be non-negative [Odd-] Radical function o√m D: ALL real numbers because we can find the oddroots of negative numbers! Rational function, f = p(x)/q(x) D: exclude roots of q(x) since q(x) ≠ 0 Logarithmic functions log m D: set m > 0 since log of 0 or negative numbers are undefined Mixed Problems D: apply as many rules as they apply...and "merge" the results! Caution! For log expressions in the denominator (1/log m), observe that log 1 = 0 → insure that m ≠ 1 by solving m = 1 Caution! (x2 + k) does not have any real solutions i.e. (x2 + k) is never 0. To solve inequalities, ALWAYS use the Number-line trick, ZOMG! NOTES start with + or – on the right-most end of the number-line depending on whether the leading term is + or - examine the exponent of the right-most root-term of the function and switch the sign on the number-line if the exponent is ODD, else the sign stays if the exponent of the corresponding root-term is EVEN proceed left-wards, repeating the 2nd step for each root on the number line Caution! After drawing the number-line and writing in the signs [+, -] we darken the region on the number-line corresponding to the inequality in the Q Write your final answers in interval notation. Copy the Q so I can do a quick assessment. a) Solve: x2 – 2x – 3 < 0 b) Solve: -x2 < -9 Tip! Move terms to left-side 1st! c) Solve: (x + 4)2(x – 4)(x + 3) > 0 d) Solve: –x2(x + 1)(x – 2)3 < 0 e) Find the D of: f = √(x2 – 5x) f) Solve: (x – 2)/(x + 1) < 0 Tip! Watch the V.A! g) Find the D of: f = log [(x – 2)/(x + 4)2 h) Find the D of f = √(9 – 4x2) Tip! Do some algebra 1st. i) Solve: (x – 4)(x – 2)3 /[(x + 1)(x + 2)2] > 0 Tip! Watch the V.A! j) Find the D of: f = log √(x – 2)2 4. <15min. Graph the following Rational functions after finding the xI, yI, V.A. and H.a. → using the Number-Line trick! NOTES For xI, y = 0 ⟹ set the top = 0 and solve for x. It may be No Solution. For yI, x = 0 ⟹ set all x-s = 0 and simplify. It may be No Solution. For V.A., find values of x such that f is undefined ⟹ set the bottom = 0 and solve. It may be No Solution. For H.A., examine end-behaviour of the function as x →±∞ while only considering the leading terms of the top and bottom. In case of 0, determine 0+ or 0-. Copy the Q so I can do a quick assessment. a) y = 1/x b) y = (x2 + 4x – 5)/(x2 + 4x – 12) c) y = 3/ (4 – x) d) y = 5/(x – 3)2 e) y = 6x/ (x – 3)2 f) y = -2x/ (x + 1) g) y = (x2 – 9)/(x2 – 1) h) y = 3x/(x2 – x – 6) i) y = 9x/(16 – x2) j) y = -5/(x2 + 10) k) y = 5x2/(x2 – 9) l) y = (x – 1) / [x(x2 – 4)] m) y = (x2 + 3)/(x2 – 9) n) y = (x2 – 9)/(x2 + 4) 5. <5min. Find the following values without a calculator. Copy the Q so I can do a quick assessment. a) cos(2π/3) b) tan (7π/6) c) sin(3π/2) d) cos(5π/4) e) cos (5π/6) f) ln (1/e2) g) ln e h) log 0.01 i) log √10 j) log5 (125) k) ln 1 l) log √10 m) ln e-3