Question

The function 't' which maps temperature in degree Celsius into temperature in degree Fahrenheit is defined by $t(C) = \frac{9c}{5} + 32.$ The value of C, when t(C) = 212.

Answer 1

the value of c is
100 degree celcius

Answer 2

The function t which maps temperature I. degree Celsius into temperature in degree Farhenhiet is defined by
$\bf{t(C)=\frac{9c}{5}+32}$

here, t(C) denotes farhenhiet and C denotes Celsius.
you should under that , C is independent variables and t(C) is dependent variable because value of t(C) depends on C.
so, we can say that. value of C is domain and value of t(C) is range of the given function.

now come to the question,
we have to find C when t(C) = 212

so, t(C) = 9C/5 + 32
212 = 9C/5 + 32
212 - 32 = 9C/5
180 = 9C/5
20 = C/5
C = 100°C

hence, temperature in Celsius 100°C when temperature in Farhenhiet 212°F.