Mathematics: Post your doubts here!

[Awesome12]

how to find the nth term in squence s
and also about the formula

a+(n-1)d
where a is the first term in the sequence, and d is the difference between 2 consecutive no.s in the sequence

for example, we have a no. sequence
5, 10, 15, 20

the first term is 5=a
the difference between 2 consecutive values is 5=d

thus the formula is
5+(n-1)5
=5n

 

[***amd***]

a+(n-1)d
where a is the first term in the sequence, and d is the difference between 2 consecutive no.s in the sequence

for example, we have a no. sequence
5, 10, 15, 20

the first term is 5=a
the difference between 2 consecutive values is 5=d

thus the formula is
5+(n-1)5
=5n

but this not the formula for all number sequences o.o

 

[Nafis Daiyan]

but this not the formula for all number sequences o.o

i was gonna say that. It's only for arithmetic sequences. For geometric sequences
nth term = ar^(n-1), where a= 1st term and r=common ratio

 

[***amd***]

i was gonna say that. It's only for arithmetic sequences. For geometric sequences
nth term = ar^(n-1), where a= 1st term and r=common ratio

hmmm... i see.

 

[Awesome12]

but this not the formula for all number sequences o.o

yes it isn't
i forgot to specify, my chrome also went down

 

[Awesome12]

i was gonna say that. It's only for arithmetic sequences. For geometric sequences
nth term = ar^(n-1), where a= 1st term and r=common ratio

what do u mean by common ratio
cud u give an example

 

[Nafis Daiyan]

yes it isn't
i forgot to specify, my chrome also went down

happens

 

[Nafis Daiyan]

the ratio between 2 consecutive terms
an example of a geometric series is
1, 5, 25, 125...
u multiply a term by 5 to get the next term...
and 5 is the common ratio

 

[Awesome12]

Awesome12
Nafis Daiyan need answer fast of higlighted text
View attachment 37051

i cant see the graph

 

[Awesome12]

F(x)=2^x
Awesome12
Nafis Daiyan

what do i have to solve?

 

[Awesome12]

f (x) = 2^x
f(x)^-1 = 1.7

(2x)^-1 = 1.7

2^-x = 1.7

2^-x = 1.7^1.3

-x=1.3
x=-1.3

 

[***amd***]

in mark scheme answer is 3.4

i got 3.249

 

[***amd***]

yes how it is given 3.1 to 3.4

have you studied Logarithms in ur maths? is it included in ur syllabus?

 

[Awesome12]

have you studied Logarithms in ur maths? is it included in ur syllabus?

i believe that is addmaths

 

[***amd***]

i believe that is addmaths

yes. but i solved it through the concept of logarithms.

so anyone got answer of it

 

[Dubi Pro]

help Please help me. i could never understand the angle properties for parallel lines.

ALSO is the line passing in this question is a transversal line??

need help with both parts urgently

 

[Awesome12]

help Please help me. i could never understand the angle properties for parallel lines.

ALSO is the line passing in this question is a transversal line??

need help with both parts urgently
View attachment 37186

now
(a) BD is parrallel to OE (given)
thus (/_ is the sign for an angle)
/_ DBC =/_ BCO (alternate angles)

OC and OB both are lines coming from the origin, thus
OC=OB
making triangle OBC an isosceles triangle
/_ OBC = /_ BCO (base angles of an isoscles triangle are equal)
/_ BCO = /_ DBC = 68
/_ BOC = 180 - 136
/_ BOC= 44

(b) triangle OCA is also an isosceles triangle
/_AOC = 180 - 44
/_AOC = 136

2 /_ ACO = 180 - 136
/_ACO = 22

/_ ACE = 180-22
= 158

 

[Dubi Pro]

now
(a) BD is parrallel to OE (given)
thus (/_ is the sign for an angle)
/_ DBC =/_ BCO (alternate angles)

OC and OB both are lines coming from the origin, thus
OC=OB
making triangle OBC an isosceles triangle
/_ OBC = /_ BCO (base angles of an isoscles triangle are equal)
/_ BCO = /_ DBC = 68
/_ BOC = 180 - 136
/_ BOC= 44

(b) triangle OCA is also an isosceles triangle
/_AOC = 180 - 44
/_AOC = 136

2 /_ ACE = 180 - 136
/_ACE = 22

the mark scheme says 154 for ACE.. Please check it, ON 2009,P22

AND also BCE and DBC can be co interior angles right? that means theey should be supplementart?? how can it be equal to 68 then? :S

 

[Dubi Pro]

now
(a) BD is parrallel to OE (given)
thus (/_ is the sign for an angle)
/_ DBC =/_ BCO (alternate angles)

OC and OB both are lines coming from the origin, thus
OC=OB
making triangle OBC an isosceles triangle
/_ OBC = /_ BCO (base angles of an isoscles triangle are equal)
/_ BCO = /_ DBC = 68
/_ BOC = 180 - 136
/_ BOC= 44

(b) triangle OCA is also an isosceles triangle
/_AOC = 180 - 44
/_AOC = 136

2 /_ ACE = 180 - 136
/_ACE = 22

also bro how is triangle OCA an isosceles triangle how can u find it and tell?

 

[Awesome12]

the mark scheme says 154 for ACE.. Please check it, ON 2009,P22

AND also BCE and DBC can be co interior angles right? that means theey should be supplementart?? how can it be equal to 68 then? :S

yes sorry i mistakenly labelled /_ ACO with /_ ACE