MATH2004C Assignment 1
Last Name: First Name:
Student ID:
• You may either write your answers on a copy of this assignment, or on your own
paper or on your electronic devices (you do not need to copy the questions).
• Due date: Sunday, Fe
uary 6th, at 10pm.
• The assignment is out of 40 points
• No email submission will be accepted.
• No excuses regarding technical issues will be accepted. It is your responsibility
to double check that you submitted the right file. Don’t wait until too close to
the deadline to start working.
• Submission Requirements: Submit your work as only one .pdf document.
Files in format different then .pdf or that are not in one document will not
e marked and you will obtain 0. Submit your file at the appropriate link on
Brightspace.
• If you have changes after submission, you can resubmit before the deadline.
Only the last submitted file before the deadline will be marked.
• In the next page, you must certified that this is your own work by signing at
the different places.
• You .pdf must be legible. The questions must be in the right order and the files
should have the co
ect orientation
• Your file must be the following format: LastName,FirstName/Name of file. Fo
example, if my name is Matt Lemire, I would name my file as:
Lemire, Matt Assignment 1.pdf
• Show your work: Means that you must show all your steps with justification.
For example, solving an integral by submission means that you must show you
substitution. Basically, only Question 4a and Question 7a do not need any
justification and/or work to be shown.
• No decimal answers will be accepted. We only want exact and simplified answers
in the form of fractions. For example, 0.125 is not accepted but
1
8
would be.
An expression of the form
3π − 1
2
would an example of an exact answer.
• You can use the Discord forum to write privately to other people in the class
egarding answers and work but please do not post any kind of solutions o
major hints on the forum. The goal is for you to learn as much as you can
your own. It is okay to get help from others as long you understand it yourself
eventually.
Question 0a. This assignment is open book. I would kindly ask you to do this
assignment without just copying down other people answers. I would kindly ask you
to promise (code of honour) that you accept the following: I promise not to have
someone else doing my assignment. I am allowed to consult textbooks, notes, the
internet, some classmates, but I will only do so to help my understanding and not fo
others to do my work.
Signature:
(For students who do not write on a printed version of the exam, simply write 0a:
and then put your signature.)
Question 0b: By signing here, I hereby certify that I have read all the instruc-
tions and conditions on the first page and that I will follow them.
Signature:
(For students who do not write on a printed version of the exam, simply write 0b:
and then put your signature.)
Question 0c: By signing here, I hereby certify that I understand that I must submit
all my work no later than Friday Fe
uary 4th, no later than 22:00 at the appropriate
link on Brightspace. I also know that my work will not be accepted passed that day
and time.
Signature:
(For students who do not write on a printed version of the exam, simply write 0c:
and then put your signature.)
Important Trigonometric Identities:
sin2(x) + cos2(x) = 1 cos2(x) =
1 + cos(2x)
2
sin2(x) =
1− cos(2x)
2
sin(x) sin(y) =
1
2
cos(x−y)− 1
2
cos(x+y) =
1
2
cos(y−x)− 1
2
cos(x+y) = sin(y) sin(x)
cos(x) cos(y) =
1
2
cos(x−y)+ 1
2
cos(x+y) =
1
2
cos(y−x)+ 1
2
cos(x+y) = cos(y) sin(x)
sin(2x) = 2 sin(x)cos(x) cos(2x) = cos2(x)− sin2(x)
Mathieu Lemire
1. a) Find the equation of the plane that passes through the points (2, 3,−1), (3, 4, 2)
and (1,−1, 0). Show all your work. (2 points)
) Find the equation of the plane that passes through the point (1, 2, 3) and that
is parallel to the plane 4x− 3y + 2z = 1. Show your work. (1 point)
2. Find a parametrization (parametric equation or parametric curve) of the line in
space that intersect the planes 2x + y − 3z = 0 and x + y = 1. Show all your work.
(2 points)
3. A curve C in space is given as the triangle that begins at (-1,0,7) until
(5,4,-2), from (5,4,-2) to (-3,1,4) and then, from (−3, 1, 4) to (−1, 0, 7). Hence, C
can be seen as the union of the curves C1, C2 and C3, where each of C1, C2, C3 is one
side of the triangle. Give a parametrization of each of C1, C2 and C3. For each of
them, do it in such a way that each depends of a parameter t with 0 ≤ t ≤ 1. Show
all your work and make sure that the orientation of your parametrization follow the
ight direction given above. (3 points)
4. A curve C in R2 begins at (−1, 1) and ends at (6,−4). It consists of 3 curves
C1, C2 and C3.
• Curve C1 goes along the parabola y = x2 line segment from (−1, 1) and ends
at (2, 4). It involves a parameter t with 0 ≤ t ≤ 3.
• Curve C2 goes along the lower part of the circle of radius 2 center at (4, 4) from
(2, 4) to (6, 4). It involves a parameter t with π ≤ t ≤ 2π.
• Curve C3 goes the left half of the ellipse with equation
(x− 6)2
4
+
y2
16
= 1 from
(6, 4) to (6,−4). It involves a parameter t from π
2
to
3π
2
.
a) Give a sketch of the curve C. (1 point)
) Give the parametrization of each of the curves C1, C2 and C3. Don’t forget
that your parametrization must satisfy the given intervals for the param-
eter t. Show your work. (3 points)
5. Consider the parametric curve C : r(t) = (2 cot t, 2 sin2 t), where 0 < t < π.
Determine the equations of the tangent lines of that curve at the points
(
− 2√
3
,
3
2
)
and
(
2
√
3,
1
2
)
. Show all your work for each line. (4 points)
6. Find the exact value of the length of the parametric curve
(t) = (2 cos(t) − cos(2t), 2 sin(t) − sin(2t)), 0 ≤ t ≤ π
2
. Show all your work. We
expect you to show your steps when solving integrals. (4 points)
Hint:
1− cos(2x)
2
= sin2(x) for all x.
7. a) Describe each shaded section of the figures below using inequalities for r and θ.
(4 points)
) Convert the Cartesian equation 3x− y+ 2 = 0 to a Polar equation. Show all you
work. (2 points)
c) Convert the Polar equation r = 2 csc(θ) to a Polar equation. Show all your work.
(2 points)
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Cartesian
8. Find the exact area of the interior of the polar curve r = 3 + 2 sin(θ) that satisfies
x ≤ 0, y ≥ 0. Sketching the curve might be useful (but is not necessary) to fully
understand the exact area that we want. Show all your work. (4 points)
Note: The hint given for Problem 6 may be useful here too.
9. Consider the polar curves r = 2 cos(2θ) and r = 1.
a) Sketch (by hand and only by hand) the two curves on the same graph. (1 point)
) Determine two angles θ such that −π
4
≤ θ ≤ π
4
, where the two curves inter-
sect. You must find the angles alge
aically and not from your sketch. (1 point)
c) Find the exact area of the region giving all the points that are inside the first
curve and inside the second curve. Show all your work. (3 points)
10. Find the arc length of the polar curve r =
√
1 + sin(2θ), 0 ≤ θ ≤ π
4
. Show all
your work. (3 points)