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Chapter 6 : Trigonometry

Posted: Fri Mar 28, 2014 3:29 pm
by admin
Be the first to discuss this chapter!

Q1 of Warm Up Exercise

Posted: Sun Aug 18, 2019 10:02 pm
by jfu.green
Since the calculator given to us will be simple, how will I figure out that the angle is approximately 73 deg (other than eyeballing a sketch)?

Thanks!

Re: Chapter 6 : Trigonometry

Posted: Mon Aug 26, 2019 7:15 pm
by sr_vineeth_ruveneco
Hi jfu.green,

We are given the details that the hypotenuse AB = 7 and side AC = 2. This means cos A = 2/7, which is approximately 0.29.

For cosine angles of 0 degrees to 90 degrees:

cos 0 degrees = sqrt(4) / 2 = 1
cos 30 degrees = sqrt(3) / 2 = 0.87
cos 45 degrees = sqrt(2) / 2 = 0.71
cos 60 degrees = sqrt(1) / 2 = 0.5
cos 90 degrees = 0

From the initial calculation, we are looking for a value of 0.29 and from the chart above, we can see this is between angles of 60 to 90 degrees.

The only answer choice that fits within this range is D. Hope this helps!

Re: Chapter 6 : Trigonometry

Posted: Sat Jun 12, 2021 3:54 am
by Brackwom
Thanks to offer such a helpful response, keep sharing more knowledgeable content.