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severe compass Apr 5, 2023, 10:50 AM

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i dont understand what the markscheme is saying

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this is the question

soft cradle Apr 5, 2023, 11:15 AM

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Area of a triangle = (b x c x sinA)/2
Angle A is found by rearranging the cosine rule (a^2 = b^2 + c^2 - 2bccosA) to cosA = (b^2 + c^2 - a^2)/2bc
A = arccos(cosA)
Substitute a, b, and A into the area formula

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@severe compass

severe compass Apr 5, 2023, 11:27 AM

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yeah i got A as 75.1, but it is saying sin A, so that threw me off, so do I sub in what I got for A?

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@soft cradle

restive verge Apr 5, 2023, 11:27 AM

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You sub in the A you get

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But if you got the angle wrong, it’s saying they still give you marks if you get the second but right

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@severe compass

#trig