HP 40gs hp 40gs_user's guide_English_E_HDPMSG40E07A.pdf - Page 288

hp40g+.book Page 14 Friday, December 9, 2005 1:03 AM Part 1 16-14 the circle C, M will move on a curve Γ. In this exercise we will study and plot Γ. 1. Let t and m be the point on C of affix z = ei ⋅ t . Find the coordinates of M in terms of t. 2. Compare x(-t) with x(t) and y(-t) with y(t). 3. Compute x′(t) and find the variations of x over [0, π]. 4. Repeat step 3 for y. 5. Show the variations of x and y in the same table. 6. Put the points of Γ corresponding to t = 0, π/3, 2π/3 and π, and draw the tangent to Γ at these points. First go to CAS MODES screen and make t the VX variable. To do this, press to open the Equation Writer, and then press . This opens CAS MODES screen. Press variable. Type Now enter the expression 1-- ⋅ z2 - z and press 2 to select it. and delete the current T and press . Now invoke the SUBST command from the menu. Because the expression was highlighted, the SUBST command is automatically applied to it. Note that the cursor is positioned in the second parameter. Since we know that z = ei ⋅ t , we can enter this as the second parameter. Step-by-Step Examples