Math 126
Introductory Quiz Fall 2018
Write neat, concise, and accurate solutions to each of the problems. No electronic devices are allowed.
Evaluate 64.4 x 2.25.
short way (4\cdot2^{\frac{1}{2}}\psi) long way 64.4
128. ५५.१ 1288
116.1
\[\frac{12.2.8}{144.90~0}\]
Express 400/17 as a decimal, correct to the nearest hundredth.
23.5주
17400.000
17
Express [3\cdot\frac{20\cdot21\cdot41}{6}+4\cdot\frac{20\cdot21}{2}-4\cdot20] = (10(2(-4)+4\cdot21-8)) 10 (al-5-8)
(a(9+5-8)) १३५० as an integer.
Find the sum+
[\frac{7}{6}+\frac{4}{5}=\frac{39+24}{30}=\frac{59}{30}]
[1+\frac{1}{2}+1-\frac{5}{7}=2-\frac{1}{30}=\frac{51}{20}]
120 is 80% of what mumber?
0.8 \(x=1220\)
\[x=i20\cdot\frac{5}{4}=150\]
\[120\rightarrow807a-Y\]
150
List the numbers 274, 0.4389 x 274, and 2740.8722 in increasing order.
0.4389-2742749
0.8722
(multifly by
multiply by
7. Find the perimeter and area of a rectangle that has a length of 18 feet and a width of 7.5 feet.
P = 2(18 + 7.5) = 36 + 15 = 52' + 15 = 140 square feet
R
187.5=·= 28.5 = 140 square feet
8. Let f(x) = 1/2x^3 - 5/2x^2 + 4x. Compute f(4) - f(1).
y(4) - y2(1) = φ42 - 40 + 16 - (12 - 12 + 4)
al - a4 -
9. Express 4/(x+1) + 3/(2x-5) as a single fraction.
4/(x+1) + 3/(2x-5) = (8x-20+3x+3)/((x+1)(2x-5)) = (11x-17)/((x+i)(2x-5))
10. Give the values of sin(π/3), cos(π/2), and tan(π/4).
cos π/2 = 0
tan = 1
11. Use the technique of completing the square to find the vertex of the parabola y = x^2 - 6x + 20.
y = x^2 - 4x + 20 = (x-3)^2 + 11
The vertex (3, 11)
12. Find all values of x that satisfy the equation x^2 = 13x.
x^2 - 13xk = 0
κ(x-13) = 0
x = -√15, 0, √13
13. Find all values of x that satisfy the equation x²-4x=11.
x²-4x-11=0
x=(4±√(16+44))/2
=2±√15
14. Find all values of x that satisfy the equation √(x²-9)=4.
√(x²-9)=4
x²-9=16
x²=25
x=±5
15. Find the quotient when x³-2x²+7x-6 is divided by x-2
x-2√x³-2x²+7x-6
The quotient is x²-2x+3
Synthetic Division Method
1-2 7 -6
2 0 4 6
1 2 3 0
16. Evaluate lim(x→∞)(x³-4x+7)/(8+5x²+3x³).
=lim(x→∞)(1-4/x²+7/x³)/(8/x³+5/x+3) = -1/3
17. Find f'(x) if f(x)=x³-4x²+3x+e^(4x+1)+2x¹
f'(x)=3x²-8x+3+e^(4x+1)(4)+2x¹
18. Find g'(x) if g(x)=ln(x²+3x+5).
g'(x)=(2x+3)/(x²+3x+5)
19. Find F'(2) for the function F(x)=x/(x²-1)
F'(x)=(x²-1-x*2x)/(x²-1)² = -(x²+1)/(x²-1)²
F'(2)=-5/9
20. Answer true or false for each of the statements
a. (a+b)² = a² + b² (False)
b. x⁻² = √x (False)
c. √(-y)² = y (False)
d. √(x²+y²) = x+y (False)
e. (a²+b)/(ac) = (a+b)/c (False)
f. (x-y)/z = x/z - y/z (True)
21. Sketch a graph of the function given on the figure.