# Recent content by yourmom98

1. ### Coplanar vectors and linear dependance

how do i prove vectors u v w are coplanar if and only if they are linearly dependent ? i have no idea where to start.
2. ### Resource on induction

In your first post. I should check my posts more carefully. The principle is that the general equation of a series is correct if it works for a number n and is n+1 i got k^2+k+2k+2=k^2+k+2k+2 by subbing in k=n into n(n+1)/2 and then taking that and subbing that into the sequence of k+1=n and...
3. ### Resource on induction

im starting to get the hang of that now. however i have problems when trying to get the General formula of the series from the formula of the sequence. a example is that im asked to prove ((n^3)-n) is divisible by 6 for all n belongs to N by induction.
4. ### Resource on induction

The principle is that if a series it is true for any number n it is ALSO true for the number that follows n. i solved the question above and got that k^2+3k+2==k^2+3k+2 therefore i proved this series. however the sequence is not always that easy as it it just equals n how do i find the nth term...
5. ### Resource on induction

i am totally lost on this subject. like i have NO CLUE what its about or what to do or how to prove things. Can anyone recommend a good site or online resource about this induction stuff?
6. ### Combinations: C(28,2n)/C(24,2n-4)=225/11 Solve for n

i am given C(28,2n)/C(24,2n-4)=225/11 where C are combonations. i am supposed to solve for n. after subbing in n and k and simplifying i get (11*28!)/2n!=(225*24!)/(2n-4)! (i am pretty sure this is correct). i do not seem to be able to continue after that. how do i solve for n?
7. ### Perpendicular Lines in 3 Space

its aliright but i still have one more question. i do not understand how you got this: \vec a_1 -\vec a_2+ \vec b_1 t_1-\vec b_2 t_2
8. ### Perpendicular Lines in 3 Space

okay if i do a cross product of the b vectors i will get a line that is perpendicular to both of the line but only at the origin. the line does not have to necessarily come across the origin right? so this would be the like B value of my 3rd line right? now then they want me to put the line so...
9. ### Perpendicular Lines in 3 Space

i know how to get values of vector b but i don't understand how to do the calculations. i dont know how to find the a line that intersects 2 other lines and at a 90 degree angle...
10. ### Perpendicular Lines in 3 Space

i am given parametric equations of 2 lines L1 and L2 and i am asked to find the vector, parametric and symmetric equation of a line that intersects these 2 lines at 90 degrees so a line that is perpendicular to those 2 lines. how do i go about this? at first i tried converting the parametric...
11. ### Coplanar vectors problem

But i cant solve it there are too many variables. i subbed in the values for W vectors and then i expanded it so now i have like C(1)V(1)+C(1)V(2) etc.. then i added up all the V(1) vectors and ended with sumthing like V(1)[C(1)+C(2)]=0 then that led me to [C(1)+C(2)]=0 cause C would be the...
12. ### Coplanar vectors problem

The numbers in brackets are supposed to be in subscript so V(2) would be V subscript 2 and the number in front is just multiply, all the variables are vectors so they have a arrow on top. Determine if, W(1) = 2V(1) + 3V(2) , W(2) = V(2) + 2V(3) and W(3) = -V(1) - 3V(3) are coplanar i dont...
13. ### 3 Space Parallelogram

Thanks HallsofIvy for correcting me. But i dont understand if im given 3 vertices i would only know 2 vectors that form the parallelepiped and one vector that is a diagonal of the parallelepiped.
14. ### 3 Space Parallelogram

i am given the (x,y,z) coordinates of 3 sides of a parallelogram how do i go about finding the 4 coordinate. do i find the distance between points using the same way to find vectors then try to find direction angles or something like that? because there is no slope or anything to compare too...
15. ### Help simplifying derivitive

okay so how does this prove y' = y/x?