Posted by Lisa on Tuesday, April 17, 2012 at 8:00am.
Can you show us how to use law of cosines to show that theta equals inverse cosine of (a^2 + b^2 484)/(2ab) where a^2=(7+xcos a)^2 + (28xsin a)^2 and b^2=(7+xcos a)^2 + (xsin a 6)^2? Thanks

Trig  Reiny, Tuesday, April 17, 2012 at 8:59am
Lisa, saw that one last night,
confused about the angle 'a'
in xcosa and xsina.
secondly where does x come in ?
describe your triangle.
I have a triangle with sides a and b and Ø as its contained angle.
Answer This Question
Related Questions
 Calculus  use law of cosines to show that theta equals inverse cosine of (a^2...
 MathsTrig  How does sin(c+h)=sin(c)xcos(h)+cos(c)xsin(h) please explain
 Reposted: Maths  Trig  I've been told that sin(c+h)=sin(c)xcos(h)+cos(c)xsin(h...
 Trig. Law of Cosines  Show that any triangle with standard labeling... a^2+b^2+...
 Math  Trig  What familiar formula can you obtain when you use the third form ...
 trig  If cosecant of theta equals 3 and cosine of theta is less than zero, find...
 Calculus  Use theta equals inverse tangent of 28/x minus inverse tangent of 6/x...
 Calculus Help  Use logarithmic differentiation to find the derivative of the ...
 maths  Xsin(theta)Ysin(theta)=sqrtX^2+Y^2 and cos^2(theta)/a^2+sin^2(theta)/b^...
 maths  Xsin(theta)Ysin(theta)=rootX^2+Y^2 andcos^2(theta)/a^2+sin^2(theta)/b^2...
More Related Questions