Maths / Introduction to Trigonometry / Trigonometric Identities

QUESTION
 

If   large cosA+sinA=sqrt{2}cosA, Show that   large cosA-sinA=sqrt{2}sinA

EXPLANATION
Explain TypeExplanation Content
Text

CosA +sinA = √2cosAsquaring both sides.⇒(cosA + sin A)² = (√2cosA)²⇒cos²A + sin²A + 2sinAcosA = 2cos²A⇒1 - sin²A + 1 - cos²A + 2sinAcosA = 2cos²A⇒2 - 2cos²A = cos²A + sin²A - 2sinAcosA⇒2(1 - cos²A)= (cosA - sinA)²⇒ cosA - sinA = √[2sin²A]⇒cosA-sinA = √2sinAhence proved

View Contents
(Concept based Learning and Testing for [6th - 10th], NTSE, Bank & Govt. Exams)
Self Learning
Testimonials
No Preview
PARENT FEEDBACK c/o Yogansh Nyasi C/o ABHYAS Academy
 7th
Abhyas is an institute of high repute. Yogansh has taken admission last year. It creates abilities in child to prepare for competitive exams. Students are motivated by living prizes on basis of performance in Abhyas exams. He is satisfied with institute.
Back
Courses We Offer
(Concept based Learning and Testing for [6th - 10th], NTSE, Bank & Govt. Exams)