If cosA 4/5 and cosB 12/13 (A and B are both acute) Find the values of (i) sin (A+B). (ii) cos (A -B).(iii) tan (A+B). Q2. Write an angle in the first quadrant whose tangent is (a)0.8816 (b)1.9496 (c)2.0265.
in the following problem,
In a triangle ABC,if r1 is the exradius of the excircle opposite to A,r2 is the exradius of the excircle opposite to B and r3is the exradius of the excircle opposite to C....
prove that (ar1+br2+cr3)/abc=(1/r)-(1/2R)
where r is the inradius and R is the circum radius.
i tried using these formulae:
r1=(area of triangle)/(s-a)
r1=stanA/2
but i cudnt solve it.how should i start?
In a triangle ABC,if r1 is the exradius of the excircle opposite to A,r2 is the exradius of the excircle opposite to B and r3is the exradius of the excircle opposite to C....
prove that (ar1+br2+cr3)/abc=(1/r)-(1/2R)
where r is the inradius and R is the circum radius.