In Fig. 4.142, `P A ,\ Q B` and `R C` are each perpendicular to `A C` . Prove that `1/x+1/z=1/y` . (FIGURE)

In Fig.4.142,PA,QB and RC are each perpendicular to AC. Prove that (1)/(x)+(1)/(z)=(1)/(y). (FIGURE)

In Fig. 4.230, each of P A ,\ Q B ,\ R C and S D is perpendicular to l . If A B=6c m , B C=9c m , C D=12 c m and P S=36 c m , then determine P Q ,\ Q R and R S . (FIGURE)

In Fig. 4.34, A ,\ B and C are points on O P ,\ O Q and O R respectively such that A B P Q and B C Q R . Show that A C P R . (FIGURE)

If a,b and c are A.P. whereas x,y and z are in G.P. : Prove that : x^(b-c)*y^(c-a)*z^(a-b)=1 .

if a,b,c are in G.P. and a^(x)=b^(y)=c^(z) prove that (1)/(x)+(1)/(z)=(2)/(y)

In A B C and P Q R Figure, A B=P Q ,B C=Q R and C B and R Q are extended to X and Y respectively and /_A B X =/_P Q Ydot Prove that A B C~=P Q Rdot Figure

In A B C and P Q R Figure, A B=P Q ,B C=Q R and C B and R Q are extended to X and Y respectively and /_A B X = /_P Q Ydot Prove that A B C~=P Q Rdot Figure

In Fig. 10.20, the sides A B ,\ B C and C A of triangle A B C touch a circle with centre O and radius r at P ,\ Q and R respectively. (FIGURE) Prove that: 1) AB + CQ = AC + BQ

In Figure, A P || B Q\ || C R . Prove that a r\ ( A Q C)=\ a r\ (P B R)

If x = a - (1)/(a), y = b - (1)/(b) and z = c - (1)/(c ) and a, b, c are in G.P., then show that (x+z)/(y) = r + (1)/(r ) , where r is the common ratio of the G.P.