Flag General Physics> vectors...
question mark

rand r2rare unit vectors in the x-y plane making angles a and b with the positivex-axis. By considering r1 . r2r r, derivecos (a − b) = cos a cos b + sin a sin b

swapnali bordoloi , 13 Years ago
Grade
anser 1 Answers
APURV GOEL

Last Activity: 13 Years ago

if we write vectors in component form we get

R1 = R1cosa^i + R1sina^j

R2 = R2cosb^i + R2sinb^j

now taking dot product R1.R2 = (R1cosa^i + R1sina^j) . (R2cosb^i + R2sinb^j)

which is also equal to R1R2cos(a-b)

so we have R1R2cos(a-b) = (R1cosa^i + R1sina^j) . (R2cosb^i + R2sinb^j)

or cos (a − b) = cos a cos b + sin a sin b


Provide a better Answer & Earn Cool Goodies

Enter text here...
star
LIVE ONLINE CLASSES

Prepraring for the competition made easy just by live online class.

tv

Full Live Access

material

Study Material

removal

Live Doubts Solving

assignment

Daily Class Assignments


Ask a Doubt

Get your questions answered by the expert for free

Enter text here...