yea but for 1, you have to find out whether it is an arithmetic or a geometric series first. so u find out T1, T2 & T3...then u see if T3-T2=T2-T1 or if T3/T2=T2/T1 but it doesnt fit into either...so its not a geo or an arith...unless IM doin something totally wrong...
same with question 3...
can someone plz help me w/ these q's?
1. a series has the nth term given by Tn=n^3 -5. find the sum of 4 terms.
2. the sum of n terms of 214+206+198+... is 2760. evaluate n.
3. evaluate:
7
(sigma) 1/n
3
as a fraction.
==============================================...
I have a problem with these questions; if anyone knows how to do it I would be very grateful!!
1) If the sum of two roots of x (to the power 4) + 2x (to the power 3) - 8x (squared) - 18x - 9=0 is 0, find the roots of the equation.
2) Solve 2cos (cubed)x + cos (squared) x - cosx =0 for x is...