Vectors 11 • Intersections of Planes • CP1 Ex9E • 🎯

Edexcel Core Pure Year 1

Mon 2/3/20

[tariqaziz]

Mr Bicen you put down that plane 1 equals to 8, when it equals to -8 ( 13:32 ), otherwise really helpful video

[St-xsgd]

Please sir how do you get from parametric for to dot product form ?

[danielsundaram]

So glad I watched this day before CP1 test 😂

[chaska]

for the last q, you did x, y, z dot the normal vectors = P, and let z equal 1/0 to find a COMMON POINT, but you could do x, y, z dot the normal vectors = 0, and let z equal 1/0 to find a common DIRECTION VECTOR right?

[arushisharma]

Sorry how do you convert from the parametric form of an equation of a plane to the scalar dot form ie. r.n = p?

[lakisananratnarajah]

Sir, For the last question could you just do the cross product of both normal vectors of the two planes to find the direction vector between plane 1 and 2, and then use a, b, c as a general point on the line and dotting it with both planes(lambda and mu will cancel out), then use simultaneous equation like you did with putting z as 0, but putting c as 0, to find the equation of the line?

[SnikleoArobijove]

for the last q - is it possible to find a common point by doing the dot product of the general vector for the line and the normal of the plane = -8, then getting an equation in terms of lambda and mu and then finding values for both??

[francescabailey]

which instances are there when you can't times up the vector to integer form? Why can't you for the last example ?

[enzicc]

Hi sir, at 16:04 you are solving the sim eq. by eliminating the variable z, by equating it to 0 and 1, to find x and y, when would I use this strategy to solve the sim. equations over just eliminating the z by doing equation 1 - equation 2.

[joeclayton]

Hi sir for part b of the question on this video where it says show that 4i+j-7k is perpendicular to the plane, would it be possible for this vector 4i+j-7k to be perpendicular to just one of the vectors parallel to the plane( i+3j+k or 2i-j+k) and not the other, just wondering why we need to prove it’s perpendicular to both of these vectors to be perpendicular to the plane and why not just proving it’s perpendicular to one of them would suffice.

[engineeringmadeasy]

In the last question am I allowed to remove the fractions?

[engineeringmadeasy]

At 17:39 you did some subtraction. Can you I subtract the other way?

[nicolelomas]

Hi Sir, at 15:46 when solving the simultaneous equations without the graphical calculator, why did you let z=0 when you previously said that assuming z to be zero can sometimes go wrong?

[SaadKhan-xqqy]

How can you find the simultaneous without the calculator?

[zaynbye]

i think the correct answer for the last question when z = 0 would be:

𝒓 = (⁻⁴⁄₇𝒊 + ¹⁶⁄₇𝒋) + λ(17𝒊 + 30𝒋 + 14𝒌)

idk if its correct tho as im still learning the topic