Question 1~
Given a triangle with two sides of lengths 4 and 5, and the cosine of the angle between them is a root of the equation 2x^2 + 3x - 2 = 0, then the length of the third side is ( )
A. √20 B. √21 C. √22 D. √61
Hi, it's time to do math problems~~~
Replies (9)
The matter described by the original poster has nothing to do with me; it is only based on the principle of 'reading posts and replying to posts, to prosper the internet and benefit both others and oneself,' in order to contribute to 'ensuring growth, expanding domestic demand, adjusting the structure, and promoting people's livelihood,' thereby making society more and more harmonious, and even promoting greater and greater unity in the world, so as to continue the learning of past sages and bring peace for all generations.
Congratulations to the person downstairs for choosing the correct answer! In this regard, I am awarding a prize, as follows! Prize
I don't remember very well. We're studying circles and lines now, and after the monthly exam, we should move on to ellipses.
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