AkaiHanabi
Thread killer
for n=1azureus88 said:sum of all integers from 1 to 200 - sum of all multiples of 7
= (200/2)(1+200) - (28/2)(1+196)
=100(201) - 14(197)
= 17342
ok can someone do my question now.
prove, using induction n^2 - 11n +30 is bigger than or equal to 0 for n is bigger than or equal to 1, where n is integer.
1 - 11 + 30
=20
20>0
true for n=1
assume for n=k
ie k^2 - 11k +30 >0
prove for n=k+1
(k+1)^2 -11(k+1) + 30
= k^2 +2k + 1 -11k -11 +30
= k^2 -9k +20
= k^2 -9k -2k +2k +30 +10 -10
= (k^2 -11k +30) +2k -10
K^2 - 11k +30>0 from assumption
and then I got stuck =/
Find the acute angle between the lines 4y=3x+8 and y=6x-9
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