whymenotsmart

See here: https://web2.0calc.com/questions/to-go-to-sleep-oliver-counted-by-6s-starting-from

It has been answereed two years ago:)

Hope this helps, whymenotsmart :P

uh............................

You have a lot of grammar errors in the problem, and don't be rude by saying that we will immediately fail, I will not answer this problem, because you are being so rude, please rewrite your question in a more formal format!

The three smallest sums are
a+b, which is 1.
a+c, which is 2.
b+c, which is 3.

The next larger sum is a+d=4

We solve this system of 3 equations in 3 unknowns:

a + b = 1
a  + c = 2
    b + c = 3

and get a=0, b=1, and c=2

Since we know that

a + d = 4

we substitute 0 for a, and get:

0 + d = 4
    d = 4

So the only values possible are a=0, b=1, c=2, and d = 4

Answer: d can only be 4.

Hope this helps, whymenotsmart!

 

thanks, hugo, this message is very important!!

I commented on your other post, it is important.

uh......................... this is science, not math, this is a math forum, if you need to any help with your math, I am happy to help you the best I can:)

We recall that, sin3x=3sinx−4sin3x , so, the given eqn. becomes,

3sinx−4sin3x+sinx=0 .

4sinx−4sin3x=0 .

4sinx(1−sin2x)=0 .

4sinxcos2x=0 .

sinx=0,cosx=0 .

x=kπ,or,x=(2k+1)π2,k∈Z .

Hence, the Soln. Set is {kπ}∪{(2k+1)π2},k∈Z .

But, x∈[0,2π),&,sinx=0⇒x=0,π , while,

for cosx=0,such x areπ2,3π2 .

^m^ whymenotsmart.

just because you write please help shortened and lazily written, doesn't mean it sohuld be attracted more attention!

I mean, IMO, you shouldn't mark this off-topic, because science is realted to math, not as good as science as math, so......................can't answer! Sorry! ^m^ whymenotsmart, it should be a....................