If ABC is right angled at C, then the value of cos (A+B) is


Given: C = 90°


By the property of triangle, the sum of the three angles is equal to


A+B+C = 180°


A+B+90° = 180° ( C = 90° )


A+B = 90°


Thus, cos(A+B) = cos 90° = 0

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