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November 01, 2025, 07:40:42 pm

Author Topic: Finding domain and range of vector functions  (Read 1057 times)  Share 

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year12issoohard

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Finding domain and range of vector functions
« on: September 15, 2015, 12:55:09 pm »
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can anyone help me with the domain and range of its cartesian equation:
r(t) = cot(2t) i  + 3cosec(2t) j , 0<= t <= pie/4
Thank you!
« Last Edit: September 15, 2015, 01:43:51 pm by year12issoohard »

brightsky

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Re: Finding domain and range of vector functions
« Reply #1 on: September 15, 2015, 01:47:18 pm »
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x = cot(2t)
y = 3 cosec(2t)

Assuming that t ≥ 0, cot(2t) ∈ R and 3 cosec(2t) ∈ (-∞, -3] U [3, +∞). (Hint: Consider the graphs of cot(2t) and 3 cosec(2t).) Hence, domain is R and range is (-∞, -3] U [3, +∞).
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year12issoohard

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Re: Finding domain and range of vector functions
« Reply #2 on: September 15, 2015, 02:23:03 pm »
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x = cot(2t)
y = 3 cosec(2t)

Assuming that t ≥ 0, cot(2t) ∈ R and 3 cosec(2t) ∈ (-∞, -3] U [3, +∞). (Hint: Consider the graphs of cot(2t) and 3 cosec(2t).) Hence, domain is R and range is (-∞, -3] U [3, +∞).

what will it be if the range of t is from 0 to pie/4 (inclusive)? sorry i forgot to write it down in the first place  ;D

keltingmeith

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Re: Finding domain and range of vector functions
« Reply #3 on: September 15, 2015, 02:55:57 pm »
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what will it be if the range of t is from 0 to pie/4 (inclusive)? sorry i forgot to write it down in the first place  ;D
Give what brighteye wrote a closer look - try copying that, but for your t instead of t>=0. Remember that the domain is the possible x values and the range is the possible y values.