akawesome
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Hi im not sure how to do this question. I got two different answers for it. I got i+j and i got (i^2+j^2)^1/2Name:  1DFEC18C-E443-4087-8979-8844FD5C3EE3.jpeg
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JGLM
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Think of a triangle with hypotenuse 1, and two 45° angles. Then try and put that hypotenuse in vector form.
The i and j components are equal, so you can get the coefficient of both by using pythagoras - rt(2a^2)=1
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davros
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(Original post by akawesome)
Hi im not sure how to do this question. I got two different answers for it. I got i+j and i got (i^2+j^2)^1/2Name:  1DFEC18C-E443-4087-8979-8844FD5C3EE3.jpeg
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Size:  121.5 KB
Well your second answer is clearly meaningless! you're looking for a vector, so some linear combination of i and j i.e. ai + bj for some scalars a and b. Assuming by i^2 you ,actually mean |i|^2 then your second expression is just a scalar, in fact it's \sqrt{2}
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PeaceMinusOne
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What is the answer to this question?
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akawesome
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(Original post by davros)
Well your second answer is clearly meaningless! you're looking for a vector, so some linear combination of i and j i.e. ai + bj for some scalars a and b. Assuming by i^2 you ,actually mean |i|^2 then your second expression is just a scalar, in fact it's \sqrt{2}
So would the answer just be i+j ?
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akawesome
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(Original post by JGLM)
Think of a triangle with hypotenuse 1, and two 45° angles. Then try and put that hypotenuse in vector form.
The i and j components are equal, so you can get the coefficient of both by using pythagoras - rt(2a^2)=1
So is the answer i+j?
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davros
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(Original post by akawesome)
So is the answer i+j?
it's a regular octagon, so what's the angle ABC?
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akawesome
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(Original post by davros)
it's a regular octagon, so what's the angle ABC?
135 so would i have to use cosine rule?
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old_engineer
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(Original post by akawesome)
So would the answer just be i+j ?
i + j is right in terms of direction but wrong in terms of magnitude. We're dealing with a regular octagon here so all the sides have equal length.
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