Final Review

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STUDY GUIDE FOR FINAL EXAMINATION
MATH 1113
1.
Let 𝑓(π‘₯) = π‘₯ 2 − 2π‘₯. Compute the following.
(a) 𝑓(3)
(b) 𝑓(0)
(c) 𝑓(π‘Ž)
(d) 𝑓(π‘Ž + 2)
𝑓(π‘₯+β„Ž)−𝑓(π‘₯)
(e) 𝑓(π‘₯ + β„Ž)
(f)
, β„Ž≠0
β„Ž
2.
Find the domain of the following functions.
(a) 𝑓(π‘₯)π‘₯ 2 − 2π‘₯
(b) 𝑓(π‘₯) =
1
π‘₯+3
1
(c) 𝑓(π‘₯) = √π‘₯ + 3
(d) 𝑓(π‘₯) =
(e)
(g)
(i)
(k)
(f) 𝑓(π‘₯) = ln π‘₯
(h) 𝑓(π‘₯) = tan π‘₯
(j) 𝑓(π‘₯) = sin−1 π‘₯
π‘₯
𝑓(π‘₯) = 𝑒
𝑓(π‘₯) = sin π‘₯
𝑓(π‘₯) = csc π‘₯
𝑓(π‘₯) = tan−1 π‘₯
√π‘₯+3
3.
Find a simplify (𝑓 ∘ 𝑔)(π‘₯).
3
2
(a) 𝑓(π‘₯) =
; 𝑔(π‘₯) =
π‘₯+2
3π‘₯
(b) 𝑓(π‘₯) = 4π‘₯ 2 + 2π‘₯ + 8; 𝑔(π‘₯) = 2π‘₯ − 3
4.
Find the inverse of the following functions.
1
(a) 𝑓(π‘₯) = 3
(b) 𝑓(π‘₯) = π‘₯ 3 + 3
√3+π‘₯
5.
Sketch the graph of the inverse of the following function.
6.
2
Put the following equations of conic sections in standard graphing form by
completing the square. Then graph the conic sections. Give the following
information for each conic section.
Parabola: vertex, axis of symmetry, focus, and directrix.
Ellipse: center, vertices, covertices, major axis, minor axis, foci, and
eccentricity.
Hyperbola: center, vertices, transverse axis, conjugate axis, foci, and
eccentricity.
2
(a) 4π‘₯ + 𝑦 2 − 16π‘₯ + 2𝑦 + 13 = 0
(b) π‘₯ = 2𝑦 2 + 2𝑦 + 3
(c) 9π‘₯ 2 − 4𝑦 2 + 36π‘₯ + 8𝑦 − 4 = 0
7.
Find the equation, in standard form, of the parabola with vertex (7, −9) and
focus (5, −9).
8.
Find all the asymptotes of the graph of 𝑓(π‘₯) =
9.
Consider the function 𝑓(π‘₯) =
. The graph of f will have a vertical
π‘₯ 2 −4
asymptote at _______ and will have a missing point at x = __________.
5π‘₯−2
4π‘₯ 2 −7π‘₯
.
3π‘₯ 2 −5π‘₯−2
10. Find the oblique asymptote of the graph of 𝑓(π‘₯) =
π‘₯ 2 −17π‘₯+72
π‘₯+3
.
11. Suppose a radioactive substance Barnesvillium has a half-life of 77 years. If 258
grams are present initially, how much will be left after 212 years?
12. What is the half-life of a radioactive element that decays to 33% of the original
amount present in 77 years?
13. Find the balance when$19,000 is invested at an annual rate of 6% for 5 years if
the interest is compounded
(a) daily
(b) continuously.
3
14. How long will it take money to double at 17% interest compounded monthly?
15. (a) The angle of depression from a tower to a landmark is 19° and the
landmark is 400 feet below the tower. How far away is the landmark?
(b) Suppose the angle of elevation of the sun is 23.4°. Find the length of the
shadow cast by Cindy Newman who is 5.75 feet tall.
4
πœ‹
5
2
16. If cos πœƒ = − and
≤ πœƒ < πœ‹, find sec θ and cot θ.
17. Find where the graphs of the following functions have vertical asymptotes or
horizontal asymptotes or state there are no asymptotes.
(a) 𝑦 = sin π‘₯
(b) 𝑦 = tan π‘₯
(c) 𝑦 = csc π‘₯
(d) 𝑦 = cos −1 π‘₯
(e) 𝑦 = tan−1 π‘₯
18. Find the exact value of the following.
(a) sin−1 (−
√3
)
2
(c) tan−1 1
(b) cos −1 (−
√2
)
2
5πœ‹
(d) sin−1 (sin
1
(e) tan (tan−1 )
πœ‹
4
)
πœ‹
(f) cos −1 [cos (− )]
3
19. Solve the following trigonometric equations.
(a) 2 sin π‘₯ + 1 = 0
(b) 2 cos 2 π‘₯ + sin π‘₯ − 1 = 0
1
(c) cos 3π‘₯ = −
(d) tan2 π‘₯ − tan π‘₯ = 0
2
20. Approximate the solutions for each equation on the interval 0 ≤ π‘₯ < 2πœ‹. Round
your answer to four decimal places.
(a) sin π‘₯ = −0.739
(b) cos π‘₯ = 0.4201
(c) tan π‘₯ = −5.17
4
21. Establish the following trigonometric identities.
(a)
(c)
(e)
tan π‘₯
(b)
= 𝑠𝑒𝑐 π‘₯
sin π‘₯
sin π‘₯−cos π‘₯
sin π‘₯
cos π‘₯−1
sin π‘₯
= 1 − cot π‘₯
(d)
sin2 𝑑+cos2 𝑑
tan 𝑑
1−cos πœƒ
tan2 πœƒ
=
= cot 𝑑
cos2 πœƒ
cos πœƒ+1
= cot π‘₯ − csc π‘₯
22. Solve the following oblique triangles.
(a) A = 30°, b = 12, c = 16
(b) a = 3.55, b = 4.08, c = 2.83
(c) B = 62.3°, C = 51.9°, c = 11.3
(d) C = 57.47°, b = 8.841, c = 0.777
(e) A = 22°, a = 10, c = 15
23. Find the area of the triangle ABC given a = 8.5, B = 102°, and C = 27°.
24. Convert the following polar equations into rectangular equations.
(a) π‘Ÿ = √7
(b) π‘Ÿ + 4 sin πœƒ = 0
(c) π‘Ÿ = 2 tan πœƒ
25. Convert the following rectangular equations into polar equations.
(a) π‘₯ + 𝑦 = 1
(b) 𝑦 2 = 2π‘₯ − π‘₯ 2
(c) The circle centered at (0, −4) with radius 4.
26. (a) Convert (8, −
3πœ‹
4
) into rectangular coordinates.
(b) Convert (5√3, −5) into polar coordinates.
ANSWERS
1.
(a) 3
(c) π‘Ž2 − 2π‘Ž
(e) π‘₯ 2 + 2π‘₯β„Ž + β„Ž2 − 2π‘₯ − 2β„Ž
(b) 0
(d) π‘Ž2 + 2π‘Ž
(f) 2π‘₯ + β„Ž − 2
2.
(a)
(c)
(e)
(g)
(b) (−∞, −3) ∪ (−3, ∞)
(d) (−3, ∞)
(f) (0, ∞)
(−∞, ∞)
[−3, ∞)
(−∞, ∞)
(−∞, ∞)
5
(h) all real numbers except
(2𝑛+1)πœ‹
2
where n is an integer; that is, all real
πœ‹
numbers except the odd multiples of
2
(i) all real numbers except 2π‘›πœ‹ where n is an integer; that is, all real numbers
except the even multiples of π
(j) [−1, 1]
(k) (−∞, ∞)
9π‘₯
3.
(a)
(b) 16π‘₯ 2 − 44π‘₯ + 38
4.
(a) 𝑓 −1 (π‘₯) =
2+6π‘₯
1
π‘₯3
3
(b) 𝑓 −1 (π‘₯) = √π‘₯ − 3
−3
5.
6.
(a) ellipse; (π‘₯ − 2)2 +
(𝑦+1)2
4
= 1; center: (2, −1); vertices: (2, 1), (2, −3);
covertices: (1, −1), (3, −1); foci: (2, −1 + √3), (2, −1 − √3);
maj. axis: π‘₯ = 2; min. axis: 𝑦 = −1; 𝑒 =
1 2
1
5
√3
2
5
1
1
(b) parabola; (𝑦 + ) = (π‘₯ − ); vertex: ( , − ); axis of symm: 𝑦 = − ;
2
2
2
2
2
2
21
1
focus: ( , − ); directrix: π‘₯ =
8
2
(c) hyperbola;
(π‘₯+2)2
4
−
(𝑦−1)2
9
19
8
= 1; center: (−2, 1); vertices: (0, 1), (−4, 1);
foci: (−2 + √13, 1), (−2 − √13, 1); trans. axis: 𝑦 = 1; conj. axis: π‘₯ = −2;
𝑒=
√13
2
7.
(𝑦 + 9)2 = −8(π‘₯ − 7)
8.
vertical asymptotes: π‘₯ = 0, π‘₯ = ; horizontal asymptote: 𝑦 = 0
9.
vertical asymptote: π‘₯ = −2; missing point at π‘₯ = 2
7
4
10. 𝑦 = π‘₯ − 20
6
11. 38.3 grams
12. 48.14 years
13. (a) $25,646.69
(b) $25,647.32
14. 4.11 years
15. (a) 1161.68 feet
(b) 13.29 feet
5
4
4
3
16. sec πœƒ = − ; cot πœƒ = −
17. (a)
(b)
(c)
(d)
(e)
no asymptotes
(2𝑛+1)πœ‹
vertical asymptotes at π‘₯ =
where n is an integer
2
vertical asymptotes at π‘₯ = 2π‘›πœ‹where n is an integer
no asymptotes
πœ‹
πœ‹
horizontal asymptotes: 𝑦 = − , 𝑦 =
2
18. (a) −
(c)
(e)
πœ‹
2
πœ‹
(b)
3
3πœ‹
4
(d) −
4
1
(f)
πœ‹
7πœ‹
11πœ‹
7πœ‹
6
11πœ‹
19. (a) { + π‘˜2πœ‹,
6
(b) { + π‘˜2πœ‹,
6
2πœ‹
(c) { +
9
πœ‹
6
π‘˜2πœ‹ 4πœ‹
3
,
9
4
3
+ π‘˜2πœ‹, where π‘˜ is an integer}
πœ‹
+ π‘˜2πœ‹, + π‘˜2πœ‹, where π‘˜ is an integer}
+
(d) {π‘˜πœ‹, + π‘˜2πœ‹,
4
πœ‹
πœ‹
π‘˜2πœ‹
3πœ‹
4
20. (a) 3.9731, 5.4516
(c) 1.7619, 4.9036
3
2
, where π‘˜ is an integer}
+ π‘˜2πœ‹,
5πœ‹
4
+ π‘˜2πœ‹,
7πœ‹
4
+ π‘˜2πœ‹, where π‘˜ is an integer}
(b) 1.1372, 5.1459
21. The answer is in working the problems.
22. (a) B ≈ 46.94°, C ≈ 103.06°, a ≈ 8.21 (b) A ≈ 58.54°, B ≈ 78.62°, C ≈ 42.84°
(c) A ≈ 65.8°, a ≈ 13, b ≈ 13
(d) no triangle
(e) B1 ≈ 12.19°, C1 ≈ 145.81°, b1 ≈ 5.636; B2 ≈ 123.81°, C2 ≈ 34.19°, b2 ≈ 22.180
23. ≈ 20.6 square units
7
24. (a) π‘₯ + 𝑦 = 7
(c) π‘₯ 4 + π‘₯ 2 𝑦 2 − 4𝑦 2 = 0
2
2
1
(b) π‘₯ 2 + (𝑦 + 2)2 = 4
25. (a) π‘Ÿ =
cos πœƒ+sin πœƒ
(c) π‘Ÿ = −8 sin πœƒ
(b) π‘Ÿ = 2 cos πœƒ
26. (a) (−4√2, −4√2)
(b) (10, − ) , (10,
6
πœ‹
5πœ‹
6
), etc
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