WebIn a triangle, a 2+b 2+c 2=ca+ab 3. Then the triangle is: A equilateral B right angled and isosceles C right angled at A=90 0,B=60 0,C=30 0 D none of the above Hard Solution Verified by Toppr Correct option is C) We have, a 2+b 2+c 2=ca+ab 3 ⇒a 2+b 2+c 2−ca−ab 3=0 ⇒( 2a 3−b)2+(2a−c)2=0 It is possible when 2a 3−b=0 and 2a−c=0 ⇒ 3a=2b=2c 3=k (let) WebIf a+ b+ c = 0 and a2 + b2 + c2 = ab +bc +ac, then it follows that 0 = (a+ b+ c)2 = a2 +b2 +c2 +2(ab+ bc +ac), or a2 +b2 +c2 = −2(ab +bc +ac). Put this together and we will see that in fact a2 + b2 + c2 = 0, ... Infinite expansion of non-linear expressions with 3 or more variables
在 ABC中.若a2+c2=b2+ac.则∠B= . 题目和参考答案——青夏教 …
WebIf a, b, c are real numbers and a2 + b2 + c2 = 2 (a - b - c) - 3, then the value of a + b + c is Q6. The value of ( 0.7) 3 − ( 0.43) 3 ( 0.7) 2 + 0.43 × 0.7 + ( 0.43) 2 is equal to: Q7. The value of ( 281 + 119) 2 − ( 281 − 119) 2 281 × 119 is equal to which of the following? Q8. If a + b 2 = 4 and ab = 7, then the value of (a - b) = Web:在 ABC中,C=90°,AB=c,AC=b,BC=a。(1)三边之间的关系:a2+b2=c2。(勾股定理)(2)锐角之间的关系:A+B=90°;(3)边角之间的关系:(锐角三角函数定义)sinA=cosB=,cosA=sinB=,tanA=。: … can google home play radio stations
2013-2014学年高中数学人教B版必修5余弦定理(二).doc
Web:在 ABC中,C=90°,AB=c,AC=b,BC=a。(1)三边之间的关系:a2+b2=c2。(勾股定理)(2)锐角之间的关系:A+B=90°;(3)边角之间的关系:(锐角三角函数定义)sinA=cosB=,cosA=sinB=,tanA=。:在 ABC中,A、B、C为其内角,a、b、c分别表示A、B、C的对边。(1)三角形内角和:A+B+C=π。(2)正弦定理:在一个三角形中,各边和它所对角的正弦的比相等(R为 ... WebYou can use Wolfram Alpha to get some alternative forms The first two listed are (A-B-C)^2-4BC A^2-2A(B+C)+(B-C)^2 As J.M. says, it will all depend on the value of A,B and C Prove a^2+b^2+c^2=\frac{6}{5} if a+b+c=0 and a^3+b^3+c^3=a^5+b^5+c^5 WebPythagoras Theorem: (only for Right-Angled Triangles) a2 + b2 = c2. Law of Cosines: (for all triangles) a2 + b2 − 2ab cos (C) = c2. So, to remember it: think " abc ": a2 + b2 = c2, then a … can google host my email domain