TY  - BOOK
AU  - Crawford, A. M.
TI  - Programmed trigonometry: an introduction to the tangent, sine and cosine ratios
T2  - Methuen's clearway programmed books
AV  - QA531 CRA 
PY  - 1968///
CY  - London
PB  - Methuen Educational
KW  - Trigonometry
KW  - Programmed instruction
N1  - 1 The tangent ratio, 2 - Reading the table, 3 - Angles of elevation and depression, 4 - Finding the angle from the table, 5 - The sine ratio, 6 - The cosine ratio
N2  - The book is a linear programme of 160 frames introducing the main ratios in Trigonometry, the tangent, sine and cosine. It does not require the use of logarithms although it introduces the student to the use of mathematical tables
ER  -