Calc 2 - Cross Product/Parametric Equation Qs

[jlax31]

Hi all,

I attempted to answer these questions using similar examples and am getting a wrong answer. The answers may be right but I may be entering them wrong.

Anyhow:


1. Determine the parametric equations of the position of a particle with constant velocity that follows a straight line path in space if it starts at the point R( −10, 10, 6 ) and after one second it is at the point S( 10, −2, 5 ).

x (t) = My answer is -10+20t
y (t) = My answer is 10-12t
z (t) = My answer is 6-1t

Speed of particle is: My answer is sqrt(236)

2. Determine the equation of the plane in the form z = f ( x, y ) that passes through the points

P( −4, 6, 10 ), Q( −5, 9, 7 ) and R( −10, −9, 9 ). z = f ( x, y ) = My answer is (48/33)-(17/33)+(624/33) 3. Determine the equation of the plane in the form z = f ( x, y ) having vectors < −7, 3, −4 > and < −5, 5, 5 >.

and the point ( 9, −5, −4 ).

z = f ( x, y ) = My answer is (35/20) - (55/20) - 80

All help is appreciated

 

[Deleted member 4993]

Hi all,

I attempted to answer these questions using similar examples and am getting a wrong answer. The answers may be right but I may be entering them wrong.

Anyhow:


1. Determine the parametric equations of the position of a particle with constant velocity that follows a straight line path in space if it starts at the point R( −10, 10, 6 ) and after one second it is at the point S( 10, −2, 5 ).

x (t) = My answer is -10+20t
y (t) = My answer is 10-12t
z (t) = My answer is 6-1t

Speed of particle is: My answer is sqrt(236)

2. Determine the equation of the plane in the form z = f ( x, y ) that passes through the points

P( −4, 6, 10 ), Q( −5, 9, 7 ) and R( −10, −9, 9 ). z = f ( x, y ) = My answer is (48/33)-(17/33)+(624/33) 3. Determine the equation of the plane in the form z = f ( x, y ) having vectors < −7, 3, −4 > and < −5, 5, 5 >.

and the point ( 9, −5, −4 ).

z = f ( x, y ) = My answer is (35/20) - (55/20) - 80

All help is appreciated

Correct

How did you get that?

 

[jlax31]

Correct

How did you get that?

I did sqrt((-10)^2 + (10)^2 + (6)^2) as per other examples I have seen.

 

[Deleted member 4993]

I did sqrt((-10)^2 + (10)^2 + (6)^2) as per other examples I have seen.

How much is \(\displaystyle \frac{dx}{dt} \)& \(\displaystyle \frac{dy}{dt} \)& \(\displaystyle \frac{dz}{dt} \)?

Then what do you do with those?

 

[jlax31]

How much is \(\displaystyle \frac{dx}{dt} \)& \(\displaystyle \frac{dy}{dt} \)& \(\displaystyle \frac{dz}{dt} \)?

Then what do you do with those?

Oh I see. I must have misunderstood the examples...

I need to find those values that you listed and plug them in to sqrt((dx/dt)^2 + (dy/dt)^2 + (dz/dt)^2) to find the answer.

 

[HallsofIvy]

Hi all,

I attempted to answer these questions using similar examples and am getting a wrong answer. The answers may be right but I may be entering them wrong.

Anyhow:


1. Determine the parametric equations of the position of a particle with constant velocity that follows a straight line path in space if it starts at the point R( −10, 10, 6 ) and after one second it is at the point S( 10, −2, 5 ).

x (t) = My answer is -10+20t
y (t) = My answer is 10-12t
z (t) = My answer is 6-1t

Speed of particle is: My answer is sqrt(236)

the speed of the particle is \(\displaystyle \sqrt{(20)^2+ (-12)^2+ (-1)^2}= \sqrt{400+ 144+ 1}\) NOT \(\displaystyle \sqrt{236}\).

2. Determine the equation of the plane in the form z = f ( x, y ) that passes through the points and the point ( 9, −5, −4 ).

z = f ( x, y ) = My answer is (35/20) - (55/20) - 80

All help is appreciated